5.5 Part 1 Z-score Practice Due 2/13

Required

1

Nicole’s score on the Stats midterm was 82 points. The class average was 75 and the SD was 5 points.
What was her z-score?

Round your answer to three places if needed.

Required

1

The speed of cars driving past DHS were measured, where the speed limit is 50 mph. The mean of 100 readings was 53.84 mph, with a standard deviation of 5.56 mph.

How many standard deviations from the mean would a car going the speed limit be?
Hint: this is the z-score.
Round to three places.

Required

1

The speed of cars driving past DHS were measured, where the speed limit is 50 mph. The mean of 100 readings was 53.84 mph, with a standard deviation of 5.56 mph.

If a car’s z-score was +3.2, how fast was this car going?
Keep all places past the decimal, give units abbreviated (mph).

Required

1

The speed of cars driving past DHS were measured, where the speed limit is 50 mph. The mean of 100 readings was 53.84 mph, with a standard deviation of 5.56 mph.

If a car was going 39 mph, how many standard deviations from the mean (z score) would this be?
Round to three places past the decimal

Required

2

The speed of cars driving past DHS were measured, where the speed limit is 50 mph. The mean of 100 readings was 53.84 mph, with a standard deviation of 5.56 mph.

Which is more unusual, the car from #3 or the car from #4? (compare the z-scores)
Explain your answer.
Choose both correct answers below.

Required

2

Suppose your Statistics teacher reports test grades as z-scores and you got a score of 2.20 on an exam. Write a sentence explaining what that means.
Select both of the answers.

Required

1

People with z-scores greater than 2.5 on an IQ test are considered as geniuses.
IQ tests have a score of a mean of 100 and SD of 16 points.

What is the cut off score to show someone is a genius? Hint: use the z-score.

Required

3

IQ tests have a score of a mean of 100 and SD of 16 points.

If your IQ score was 122, what would your z-score be? Would this be considered unusual?
Select three correct answers.

Required

3

IQ tests have a score of a mean of 100 and SD of 16 points.

If your IQ had a z-score of +2.5, what would your IQ score be? Would this be considered unusual?
Select three correct answers.

Required

1

A TV weatherman’s end-of-year analysis of the local weather showed that among all the years for which records had been kept, the past year’s average temperature
had a z-score of 2.8.
What does that mean? Hint: what does a z-score mean?

Required

4

A highly selective university will only admit students who place at least 2 standard deviations above the mean on the ACT that follows the normal model: N(18, 6). 
What is the mean? _______ 
What is the standard deviation? _______ 

What is the z-score for the minimum score that an applicant must obtain to be admitted 
to the university? _______ 
What is the minimum score that an applicant must obtain to be admitted 
to the university? _______ 

Required

1

What if the mean score on our Stats Quiz yesterday was 75 points (hopefully not!) with a standard deviation of 5 points. If Marc’s z-score was 1.9, how many points did he score on the quiz?

Required

3

What if the mean score on our Stats Quiz yesterday was 75 points (hopefully not!) with a standard deviation of 5 points. If Cici scored a 78 on the Stats Quiz and a 86 on a Government Quiz that had a mean score of 83 and a standard deviation of 7 points, on which quiz did she score better on?
Calculate your work & explain. Hint: use z-scores to compare.
Choose all three correct answers.

Required

3

A manufacturer of bolts has a quality control policy that requires it to destroy any bolts that are more than 2 standard deviations from the mean. 
The quality control engineer knows that the bolts coming off the assembly line have a mean length of 8cm with a standard deviation of 0.05 cm. 
For what length will a bolt be destroyed? 
Hint: you need to create an upper and a lower length that will cause the quality control engineer to throw away a bolt.

Shorter length for bolts to be thrown out: _______ 
Longer length for bolts to be thrown out: _______ include units!

Required

4

SAT vs. ACT- If you took the SAT and scored 550, and your friend took the ACT and scored 30. The SAT has a mean of 500 and a standard deviation of 100.
The ACT has a mean of 18 and a standard deviation of 6.

Which score is better?
Give the z scores.
Then explain.
Select 4 answers.

Nicole’s score on the Stats midterm was 82 points. The class average was 75 and the SD was 5 points. What was her z-score?Round your answer to three places if needed.

The speed of cars driving past DHS were measured, where the speed limit is 50 mph. The mean of 100 readings was 53.84 mph, with a standard deviation of 5.56 mph.How many standard deviations from the mean would a car going the speed limit be? Hint: this is the z-score.Round to three places.

The speed of cars driving past DHS were measured, where the speed limit is 50 mph. The mean of 100 readings was 53.84 mph, with a standard deviation of 5.56 mph.If a car’s z-score was +3.2, how fast was this car going?Keep all places past the decimal, give units abbreviated (mph).

The speed of cars driving past DHS were measured, where the speed limit is 50 mph. The mean of 100 readings was 53.84 mph, with a standard deviation of 5.56 mph.If a car was going 39 mph, how many standard deviations from the mean (z score) would this be?Round to three places past the decimal

The speed of cars driving past DHS were measured, where the speed limit is 50 mph. The mean of 100 readings was 53.84 mph, with a standard deviation of 5.56 mph.Which is more unusual, the car from #3 or the car from #4? (compare the z-scores) Explain your answer.Choose both correct answers below.

Suppose your Statistics teacher reports test grades as z-scores and you got a score of 2.20 on an exam. Write a sentence explaining what that means.Select both of the answers.

People with z-scores greater than 2.5 on an IQ test are considered as geniuses. IQ tests have a score of a mean of 100 and SD of 16 points. What is the cut off score to show someone is a genius? Hint: use the z-score.

IQ tests have a score of a mean of 100 and SD of 16 points. If your IQ score was 122, what would your z-score be? Would this be considered unusual?Select three correct answers.

IQ tests have a score of a mean of 100 and SD of 16 points. If your IQ had a z-score of +2.5, what would your IQ score be? Would this be considered unusual?Select three correct answers.

A TV weatherman’s end-of-year analysis of the local weather showed that among all the years for which records had been kept, the past year’s average temperature had a z-score of 2.8. What does that mean? Hint: what does a z-score mean?

What if the mean score on our Stats Quiz yesterday was 75 points (hopefully not!) with a standard deviation of 5 points. If Marc’s z-score was 1.9, how many points did he score on the quiz?

SAT vs. ACT- If you took the SAT and scored 550, and your friend took the ACT and scored 30. The SAT has a mean of 500 and a standard deviation of 100. The ACT has a mean of 18 and a standard deviation of 6. Which score is better? Give the z scores.Then explain.Select 4 answers.

Nicole’s score on the Stats midterm was 82 points. The class average was 75 and the SD was 5 points.
What was her z-score?

Round your answer to three places if needed.

The speed of cars driving past DHS were measured, where the speed limit is 50 mph. The mean of 100 readings was 53.84 mph, with a standard deviation of 5.56 mph.

How many standard deviations from the mean would a car going the speed limit be?
Hint: this is the z-score.
Round to three places.

The speed of cars driving past DHS were measured, where the speed limit is 50 mph. The mean of 100 readings was 53.84 mph, with a standard deviation of 5.56 mph.

If a car’s z-score was +3.2, how fast was this car going?
Keep all places past the decimal, give units abbreviated (mph).

The speed of cars driving past DHS were measured, where the speed limit is 50 mph. The mean of 100 readings was 53.84 mph, with a standard deviation of 5.56 mph.

If a car was going 39 mph, how many standard deviations from the mean (z score) would this be?
Round to three places past the decimal

Suppose your Statistics teacher reports test grades as z-scores and you got a score of 2.20 on an exam. Write a sentence explaining what that means.
Select both of the answers.

People with z-scores greater than 2.5 on an IQ test are considered as geniuses.
IQ tests have a score of a mean of 100 and SD of 16 points.

What is the cut off score to show someone is a genius? Hint: use the z-score.

IQ tests have a score of a mean of 100 and SD of 16 points.

If your IQ score was 122, what would your z-score be? Would this be considered unusual?
Select three correct answers.

IQ tests have a score of a mean of 100 and SD of 16 points.

If your IQ had a z-score of +2.5, what would your IQ score be? Would this be considered unusual?
Select three correct answers.

A TV weatherman’s end-of-year analysis of the local weather showed that among all the years for which records had been kept, the past year’s average temperature
had a z-score of 2.8.
What does that mean? Hint: what does a z-score mean?

SAT vs. ACT- If you took the SAT and scored 550, and your friend took the ACT and scored 30. The SAT has a mean of 500 and a standard deviation of 100.
The ACT has a mean of 18 and a standard deviation of 6.

Which score is better?
Give the z scores.
Then explain.
Select 4 answers.