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5.2 Mean and Standard Deviation of Discrete RV

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Last updated about 1 month ago
11 questions
1
1
1
1
Use the following situation to answer questions 1-4:
El Dorado Community College considers a student to be full-time if he or she is taking between 12 and 18 hours. The tuition charge for a full time student is $50 per hour. Suppose we choose a full-time student at random. The probability distribution for the random variable T = tuition charge for the chosen student is shown here.
Question 1
1.

Make a histogram of the probability distribution.

Question 2
2.

Describe the shape of the histogram of the variable T.

Question 3
3.

Calculate the mean of T.

Question 4
4.

Calculate the standard deviation of T.

Use the following situation to answer questions 5-8:
Ana is a dedicated Skee Ball player who always rolls for the 50-point slot. The probability distribution of Ana's score X on a randomly selected roll of the ball is shown here.
1
Question 5
5.

Calculate the mean of X.

2
Question 6
6.
Interpret the mean of X.

If we pick many, many of Ana's randomly selected _______, the average _______ will be about _______(mean) _______(units).
2
Use the following situation to answer questions 9-11:
Casey decides to apply for a job selling mobile phones. She receives a base salary of $200 per month and $15 for every phone sold. The following table shows the probability of a particular number of mobile phones, x, being sold per month.

2
Question 8
8.
Calculate the average number of cell phones Casey can expect to sell. _______

If Casey sells this many cell phones, how much would she make? _______

3
Question 9
9.
2
Question 10
10.
The random variable X is the number of houses sold by Christine in a single month at the Oppenheim Group. Its probability distribution is as follows.


1
Question 11
11.

What is the average number of houses sold Christine in a single month at the Oppenheim Group?

Question 7
7.
The standard deviation is 12.6. Interpret the standard deviation of X. Round the mean and standard deviation to one decimal place.

Ana's _______ typically varies by about _______(standard deviation) _______(units) from the mean of _______(mean) _______(units).
Interpret the mean of X.

If we pick many, many of Casey's randomly selected work months, the average number of _______ sold will be about _______(mean) _______(units).
The standard deviation is 53.86. Interpret the standard deviation of X. Round the mean and standard deviation to two decimal places.

The number of _______ sold typically varies by about _______(standard deviation) _______(units) from the mean of _______(mean) _______(units).