Unit 8 Day 10 Sample Space and Probability Practice

The following information is to familiarize you with a standard deck of cards:

The cards that are part of a standard deck of 52 cards are pictured above. (no jokers included in most games)
Note:  52 cards in the deck
            2 colors: black and red
            26 cards of each color (26 black & 26 red)
            4 suits: hearts, diamonds, spades, clubs (clovers)
            2 red suits: hearts & diamonds
            2 black suits: spades & clubs
            13 cards in each suit: Ace through K (sometimes ace is highest and sometimes it is lowest card in the suit)
            3 face cards of each suit (Jack, Queen, King)
            

4

You draw a card from a well shuffled deck of cards and record the suit.

1. select the sample space
2. do you think the events in the sample space are equally likely?

4

You shake a coin out of a piggy bank containing a quarter, a penny, a dime and a nickel; record the value.

1. select the sample space
2. do you think the events in the sample space are equally likely?

4

You toss 2 fair coins; record the order of heads and tails for the flips.

1. select the sample space
2. do you think the events in the sample space are equally likely?

4

You roll 2 dice; record the larger number. If it is a tie, then that number is recorded.

1. select the sample space
2. do you think the events in the sample space are equally likely?
Think about all the different ways you can get the outcomes.

4

You toss a coin 10 times; record the length of the longest run of heads.

1. select the sample space
2. do you think the events in the sample space are equally likely?
Think about all the different ways you can get the outcomes.

4

You roll a fair 6 sided die; record the number rolled.

1. select the sample space
2. do you think the events in the sample space are equally likely?

4

You roll a fair 6 sided die; record if the number is odd or even.

1. select the sample space
2. do you think the events in the sample space are equally likely?

4

You roll a fair 6 sided die; record if the number is divisible by three.

1. select the sample space
2. do you think the events in the sample space are equally likely?

4

You roll a fair 6 sided die three times; record the number of 5's rolled.

1. select the sample space
2. do you think the events in the sample space are equally likely?

8

There are four basic blood types: A, B, AB and O.
Use the 'show your work section to create a sample space showing all the possible pairings for a set of parents.

For credit you need to show the sample space!

8

A large basket contains brightly colored eggs that are pink, blue, orange & yellow.
Young children are told they can choose 2 eggs to open.
Use the 'show your work section to create a sample space showing all the possible pairings for a child could choose.

For credit you need to show the sample space!

8

A family has decided that they would like to adopt two cats from the Humane Society, they can adopt tabby, black, white or calico colored cats.
Use the 'show your work section to create a sample space showing all the possible pairings for the coloring of the two adopted cats.

For credit you need to show the sample space!

4

Use the sample space from the previous question:

Are the outcomes equally likely?
How do you know?

For full credit you need to answer both questions!

4

Anitra has played the lottery every week for many years and has never won a major prize.
Each time she loses, she says she is getting closer to someday winning that prize.
Comment on her reasoning using information we have discussed in class.

4

A company is testing their batteries in digital cameras to see if they last long enough to take 500 pictures. Each day they test 20 batteries and graph the overall percentage of the batteries that have failed the test so far.

Estimate the probability that one of the company’s batteries will fail before taking 500 pictures with a digital camera. __________ Explain your reasoning.
Ignore the letter 'A' on the graph.

4

A company is testing a newly developed coin to be used in the Super Bowl to determine which team gets to choose how they will start the game.

Estimate the probability that a flip of the coin will give heads. __________
Explain your reasoning.

4

A company is testing a newly developed coin to be used in the Super Bowl to determine which team gets to choose how they will start the game.

Estimate the probability that a flip of the coin will give heads. __________
Explain your reasoning.

4

A company is testing a newly developed coin to be used in the Super Bowl to determine which team gets to choose how they will start the game.

Estimate the probability that a flip of the coin will give heads. __________
Explain your reasoning.

4

What Statistical law is being illustrated in the previous question?

4

The coach of the football team needs to choose a kicker for a critical field goal in the championship game. These are his choices and strategies.
Choose Donnie because he missed his last five shots over the last several games. He’s due to make this field goal.
Choose Ronnie because he has made his last three kicks earlier in the game so he’s “on a roll” tonight.
Choose Lonnie because he has the highest overall season percentage of making field goals.
Based on your understanding of probability, which is the best strategy _____ and why?
Answer both questions for full credit.

4

The coach of the football team needs to choose a kicker for a critical field goal in the championship game. These are his choices and strategies.
Choose Ronnie because he missed his last five shots over the last several games. He’s due to make this field goal.
Choose Lonnie because he has made his last three kicks earlier in the game so he’s “on a roll” tonight.
Choose Donnie because he has the highest overall season percentage of making field goals.
Based on your understanding of probability, which is the best strategy _____ and why?
Answer both questions for full credit.

4

The coach of the football team needs to choose a kicker for a critical field goal in the championship game. These are his choices and strategies.
Choose Lonnie because he missed his last five shots over the last several games. He’s due to make this field goal.
Choose Donnie because he has made his last three kicks earlier in the game so he’s “on a roll” tonight.
Choose Ronnie because he has the highest overall season percentage of making field goals.
Based on your understanding of probability, which is the best strategy _____ and why?
Answer both questions for full credit.

4

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards).
We will calculate the total number of hands possible.
Is this a combination or permutation? Why?

4

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards).

What set up will you put into the calculator to find the total number of hands possible?

4

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards).

How many different hands are possible?
Use commas in your answer.

4

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards).
Refer to the picture and information at the beginning of the quiz, how many cards are hearts?

4

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards).
We want to know how many hands contain only hearts.

First: What is the setup you will put in your calculator to determine how many hands can be made from only hearts?
Use the Math keyboard for subscript numbers (far right, second row down), use the arrow key to get out of the subscript level.

4

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards). How many hands contain only hearts?

Now do the calculation.
How many hands contain only hearts?
Use commas in your answer.

4

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards).
What's the probability you will be dealt a hand that is all hearts?
Remember:

Note: negative E (-E) means move the decimal point over to the left that many places.
Give your answer as a decimal (rounded to 4 places this time) or as a percent (rounded to two places past the decimal point this time ).

4

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards).
How many different hands will give you a flush (cards that are all the same suit).

Hint: this meaans 'all hearts OR all spades OR all clubs OR all diamonds' is what we want.
Use the answers from previous questions to help you find your answer.

Write your answer with commas.

4

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards).
What is the probability that you will get a fush?

Use the answers from previous questions to help you find your answer.
Hint:

Write your answer as a decimal (rounded to 3 places) or as a percent (rounded to one place past the decimal).

4

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards).
Is this a combination or permutation? Why?

4

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards).

What set up will you put into the calculator to find the total number of hands possible?

4

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards).

How many different hands are possible?
Include commas in your answer.

4

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards).
How many cards in the deck are NOT hearts?

4

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards).
How many of those hands DO NOT contain any hearts? (contain no hearts)
Hint: use the information from the previous question.

Enter your answer with commas.

4

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards).

What is the probability that your hand will contain no hearts?

Use P(at least one heart) = # hands with no hearts
Total # hands possible

Enter your answer as a decimal (rounded to three places) or as a percent (rounded to one place past the decimal).

4

Your American Literature class will read 4 novels this year, chosen by a class vote from a list of 12 possible books offered by the teacher.

How many different choices of books could the class read? Hint: first you need to decide is this a permutation or combination? Then calculate using 'math' 'prob'
Use commas in your answer if needed

4

Your American Literature class will read 4 novels this year, chosen by a class vote from a list of 12 possible books offered by the teacher. Students will vote on the novels they prefer. The top four novels will be read from the most popular to the least.

How many different ways could the course unfold? Hint: You need to decide, is this a permutation or combination?
Use commas in your answer if needed.

4

A swim coach has 7 swimmers that he is teaching to be part of a 4-person relay team.

How many different groups of 4 swimmer groups can the coack make?
Hint: You need to decide if this is a permutation or a combination.

4

A swim coach is considering 7 swimmers as possible members of a 4-person relay team.

The coach will use strategy to put together the relay team, for example usually the fastest swimmers are the lead and the anchor swimmers.
How many different relays can he put together?
Hint: you need to decide if this is a permutation or a combination.

4

George has gone shopping at HEB with his little sister, Anna, to pick out some Blue Bell ice cream for their Easter dinner. There are 16 different flavors they can pick from. If George lets Anna choose 3 different flavors, how many groups of 3 flavors can she pick?

Hint: you need to decide if this is a permutation or a combination.
Enter your answer below.

4

George is taking his little sister, Anna, to Coldstone Creamery to get some gourmet ice cream. Today Coldstone has 21 flavors. Anna wants to get a triple cone and is specific about what flavor is on top, the middle and the bottom.
How many different cones can Anna get if she likes all 21 flavors?
Hint: you need to decide, is this a permutation or a combination?
Enter your answer below.

4

A scratch off lottery ticket has 12 concealed spaces among which are 4 symbols saying ‘Win!’.
Is this a combination or permutation? Why?

4

A scratch off lottery ticket has 12 concealed spaces among which are 4 symbols saying ‘Win!’.
What set up will you put into the calculator to find the total number of groups possible?

4

A scratch off lottery ticket has 12 concealed spaces among which are 4 symbols saying ‘Win!’.

How many groups are possible for scratching off three of the 12 spaces on the lottery ticket?

4

A scratch off lottery ticket has 12 concealed spaces among which are 4 symbols saying ‘Win!’.
The person who bought the ticket scratches off three spaces, winning an instant $10 if all three are winners.

How many different groups are possible for scratching off three of the four ‘Win!’ spaces?

4

A scratch off lottery ticket has 12 concealed spaces among which are 4 symbols saying ‘Win!’. The person who bought the ticket scratches off three spaces, winning an instant $10 if all three are winners.

Use the information in the previous two questions to calculate the probability of winning $10 in the game.
Enter your answer as a decimal (rounded to three places) or as a percent (rounded to one place past the decimal).

4

There are 5 different burgers, 3 sizes of fries and 8 different milkshakes on the menu at Shake Shack. How many ways can your order one burger, one order of fries and one milkshake?

4

There are 5 different burgers, 3 sizes of fries and 8 different milkshakes on the menu at Shake Shack. How many ways can your order one burger or one order of fries or one milkshake?

4

There are 6 different burgers, 3 sizes of fries and 8 different milkshakes on the menu at Shake Shack. How many ways can you order one burger or one order of fries or one milkshake?

4

There are 6 different burgers, 3 sizes of fries and 8 different milkshakes on the menu at Shake Shack. How many ways can you order one burger, 1 order of fries and one milkshake?

4

According to the Book of Odds, the probability that a randomly selected U.S. adult usually eats breakfast is 0.61.
Explain what the probability means in this setting.
Think of class discussions about interpreting probability.

4

A husband and wife decide to have children until they have at least one child of each gender. The couple has seven girls in a row. Their doctor assured them that they were much more likely to have a boy for their next child after all those girls.
Do you think the doctor is correct? Explain using statistics and what we have discussed in class.

4

The airline industry proudly announces that it has set a new record for the longest period of safe flights with no problems. Would you be reluctant to fly?
Are the airlines due to have a crash? Explain using statistics and what we have discussed in class.

4

In the National Health and Nutrition Examination Survey of 2017-2018 the Harvard School of Public Health found that the probability a randomly selected American adult is over weight is 71.6%.
Explain the meaning of this probability in this context using ideas we have discussed in class.

4

A survey by Fact Tank found that the probability that a randomly selected American adult uses Facebook is 69%.
Explain the meaning of this probability in this context using ideas we have discussed in class.

4

The U.S. Census in 2019 found that the probability that a randomly selected person in the US if over 65 years is 16.5%.
Explain the meaning of this probability in this setting using ideas we have discussed in class.

You draw a card from a well shuffled deck of cards and record the suit.1. select the sample space2. do you think the events in the sample space are equally likely?

You shake a coin out of a piggy bank containing a quarter, a penny, a dime and a nickel; record the value.1. select the sample space2. do you think the events in the sample space are equally likely?

You toss 2 fair coins; record the order of heads and tails for the flips.1. select the sample space2. do you think the events in the sample space are equally likely?

You roll 2 dice; record the larger number. If it is a tie, then that number is recorded.1. select the sample space2. do you think the events in the sample space are equally likely?Think about all the different ways you can get the outcomes.

You toss a coin 10 times; record the length of the longest run of heads. 1. select the sample space2. do you think the events in the sample space are equally likely?Think about all the different ways you can get the outcomes.

You roll a fair 6 sided die; record the number rolled. 1. select the sample space2. do you think the events in the sample space are equally likely?

You roll a fair 6 sided die; record if the number is odd or even. 1. select the sample space2. do you think the events in the sample space are equally likely?

You roll a fair 6 sided die; record if the number is divisible by three. 1. select the sample space2. do you think the events in the sample space are equally likely?

You roll a fair 6 sided die three times; record the number of 5's rolled. 1. select the sample space2. do you think the events in the sample space are equally likely?

There are four basic blood types: A, B, AB and O.Use the 'show your work section to create a sample space showing all the possible pairings for a set of parents.For credit you need to show the sample space!

A large basket contains brightly colored eggs that are pink, blue, orange & yellow.Young children are told they can choose 2 eggs to open.Use the 'show your work section to create a sample space showing all the possible pairings for a child could choose.For credit you need to show the sample space!

Use the sample space from the previous question:Are the outcomes equally likely? How do you know?For full credit you need to answer both questions!

Anitra has played the lottery every week for many years and has never won a major prize. Each time she loses, she says she is getting closer to someday winning that prize. Comment on her reasoning using information we have discussed in class.

A company is testing a newly developed coin to be used in the Super Bowl to determine which team gets to choose how they will start the game. Estimate the probability that a flip of the coin will give heads. __________ Explain your reasoning.

A company is testing a newly developed coin to be used in the Super Bowl to determine which team gets to choose how they will start the game. Estimate the probability that a flip of the coin will give heads. __________ Explain your reasoning.

A company is testing a newly developed coin to be used in the Super Bowl to determine which team gets to choose how they will start the game. Estimate the probability that a flip of the coin will give heads. __________ Explain your reasoning.

What Statistical law is being illustrated in the previous question?

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards). We will calculate the total number of hands possible.Is this a combination or permutation? Why?

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards). What set up will you put into the calculator to find the total number of hands possible?

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards). How many different hands are possible? Use commas in your answer.

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards). Refer to the picture and information at the beginning of the quiz, how many cards are hearts?

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards). How many hands contain only hearts?Now do the calculation.How many hands contain only hearts?Use commas in your answer.

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards).Is this a combination or permutation? Why?

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards). What set up will you put into the calculator to find the total number of hands possible?

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards). How many different hands are possible?Include commas in your answer.

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards). How many cards in the deck are NOT hearts?

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards). How many of those hands DO NOT contain any hearts? (contain no hearts)Hint: use the information from the previous question.Enter your answer with commas.

A swim coach has 7 swimmers that he is teaching to be part of a 4-person relay team.How many different groups of 4 swimmer groups can the coack make?Hint: You need to decide if this is a permutation or a combination.

A scratch off lottery ticket has 12 concealed spaces among which are 4 symbols saying ‘Win!’.Is this a combination or permutation? Why?

A scratch off lottery ticket has 12 concealed spaces among which are 4 symbols saying ‘Win!’.What set up will you put into the calculator to find the total number of groups possible?

A scratch off lottery ticket has 12 concealed spaces among which are 4 symbols saying ‘Win!’. How many groups are possible for scratching off three of the 12 spaces on the lottery ticket?

There are 5 different burgers, 3 sizes of fries and 8 different milkshakes on the menu at Shake Shack. How many ways can your order one burger, one order of fries and one milkshake?

There are 5 different burgers, 3 sizes of fries and 8 different milkshakes on the menu at Shake Shack. How many ways can your order one burger or one order of fries or one milkshake?

There are 6 different burgers, 3 sizes of fries and 8 different milkshakes on the menu at Shake Shack. How many ways can you order one burger or one order of fries or one milkshake?

There are 6 different burgers, 3 sizes of fries and 8 different milkshakes on the menu at Shake Shack. How many ways can you order one burger, 1 order of fries and one milkshake?

According to the Book of Odds, the probability that a randomly selected U.S. adult usually eats breakfast is 0.61.Explain what the probability means in this setting.Think of class discussions about interpreting probability.

The airline industry proudly announces that it has set a new record for the longest period of safe flights with no problems. Would you be reluctant to fly?Are the airlines due to have a crash? Explain using statistics and what we have discussed in class.

In the National Health and Nutrition Examination Survey of 2017-2018 the Harvard School of Public Health found that the probability a randomly selected American adult is over weight is 71.6%.Explain the meaning of this probability in this context using ideas we have discussed in class.

A survey by Fact Tank found that the probability that a randomly selected American adult uses Facebook is 69%.Explain the meaning of this probability in this context using ideas we have discussed in class.

The U.S. Census in 2019 found that the probability that a randomly selected person in the US if over 65 years is 16.5%.Explain the meaning of this probability in this setting using ideas we have discussed in class.

You draw a card from a well shuffled deck of cards and record the suit.

1. select the sample space
2. do you think the events in the sample space are equally likely?

You shake a coin out of a piggy bank containing a quarter, a penny, a dime and a nickel; record the value.

1. select the sample space
2. do you think the events in the sample space are equally likely?

You toss 2 fair coins; record the order of heads and tails for the flips.

1. select the sample space
2. do you think the events in the sample space are equally likely?

You roll 2 dice; record the larger number. If it is a tie, then that number is recorded.

1. select the sample space
2. do you think the events in the sample space are equally likely?
Think about all the different ways you can get the outcomes.

You toss a coin 10 times; record the length of the longest run of heads.

1. select the sample space
2. do you think the events in the sample space are equally likely?
Think about all the different ways you can get the outcomes.

You roll a fair 6 sided die; record the number rolled.

1. select the sample space
2. do you think the events in the sample space are equally likely?

You roll a fair 6 sided die; record if the number is odd or even.

1. select the sample space
2. do you think the events in the sample space are equally likely?

You roll a fair 6 sided die; record if the number is divisible by three.

1. select the sample space
2. do you think the events in the sample space are equally likely?

You roll a fair 6 sided die three times; record the number of 5's rolled.

1. select the sample space
2. do you think the events in the sample space are equally likely?

There are four basic blood types: A, B, AB and O.
Use the 'show your work section to create a sample space showing all the possible pairings for a set of parents.

For credit you need to show the sample space!

Use the sample space from the previous question:

Are the outcomes equally likely?
How do you know?

For full credit you need to answer both questions!

Anitra has played the lottery every week for many years and has never won a major prize.
Each time she loses, she says she is getting closer to someday winning that prize.
Comment on her reasoning using information we have discussed in class.

A company is testing a newly developed coin to be used in the Super Bowl to determine which team gets to choose how they will start the game.

Estimate the probability that a flip of the coin will give heads. __________
Explain your reasoning.

A company is testing a newly developed coin to be used in the Super Bowl to determine which team gets to choose how they will start the game.

Estimate the probability that a flip of the coin will give heads. __________
Explain your reasoning.

A company is testing a newly developed coin to be used in the Super Bowl to determine which team gets to choose how they will start the game.

Estimate the probability that a flip of the coin will give heads. __________
Explain your reasoning.

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards).
We will calculate the total number of hands possible.
Is this a combination or permutation? Why?

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards).

What set up will you put into the calculator to find the total number of hands possible?

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards).

How many different hands are possible?
Use commas in your answer.

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards).
Refer to the picture and information at the beginning of the quiz, how many cards are hearts?

You’re playing poker with some friends, and are about to be dealt 5 cards from a well shuffled standard deck of cards (52 cards). How many hands contain only hearts?

Now do the calculation.
How many hands contain only hearts?
Use commas in your answer.

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards).
Is this a combination or permutation? Why?

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards).

What set up will you put into the calculator to find the total number of hands possible?

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards).

How many different hands are possible?
Include commas in your answer.

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards).
How many cards in the deck are NOT hearts?

You’re playing hearts with some friends, and are about to be dealt 7 cards from a well shuffled standard deck of cards (52 cards).
How many of those hands DO NOT contain any hearts? (contain no hearts)
Hint: use the information from the previous question.

Enter your answer with commas.

A swim coach has 7 swimmers that he is teaching to be part of a 4-person relay team.

How many different groups of 4 swimmer groups can the coack make?
Hint: You need to decide if this is a permutation or a combination.

A scratch off lottery ticket has 12 concealed spaces among which are 4 symbols saying ‘Win!’.
Is this a combination or permutation? Why?

A scratch off lottery ticket has 12 concealed spaces among which are 4 symbols saying ‘Win!’.
What set up will you put into the calculator to find the total number of groups possible?

A scratch off lottery ticket has 12 concealed spaces among which are 4 symbols saying ‘Win!’.

How many groups are possible for scratching off three of the 12 spaces on the lottery ticket?

According to the Book of Odds, the probability that a randomly selected U.S. adult usually eats breakfast is 0.61.
Explain what the probability means in this setting.
Think of class discussions about interpreting probability.

The airline industry proudly announces that it has set a new record for the longest period of safe flights with no problems. Would you be reluctant to fly?
Are the airlines due to have a crash? Explain using statistics and what we have discussed in class.

In the National Health and Nutrition Examination Survey of 2017-2018 the Harvard School of Public Health found that the probability a randomly selected American adult is over weight is 71.6%.
Explain the meaning of this probability in this context using ideas we have discussed in class.

A survey by Fact Tank found that the probability that a randomly selected American adult uses Facebook is 69%.
Explain the meaning of this probability in this context using ideas we have discussed in class.

The U.S. Census in 2019 found that the probability that a randomly selected person in the US if over 65 years is 16.5%.
Explain the meaning of this probability in this setting using ideas we have discussed in class.