The data below represent the means from 15 sample control charts for the amount of time in minutes it takes students to complete a quiz in a basic statistics course.The same quiz was given to 15 different sections of a basic statistics course.Five students were sampled from each class and each mean is shown below. What is the approximate value of the center line for the correct control chart?
A)16.71
B)2.83
C)9.77
D)None of the above

Question

The data below represent the means from 15 sample control charts for the amount of time in minutes it takes students to complete a quiz in a basic statistics course.The same quiz was given to 15 different sections of a basic statistics course.Five students were sampled from each class and each mean is shown below.  What is the approximate value of the center line for the correct control chart?
A)16.71 
B)2.83 
C)9.77 
D)None of the above

Quizplus · Accepted Answer

The center line of a control chart is the average of the sample means. We can find this by taking the mean of the 15 sample means given: (16.08+8.97+12.24+15.97+17.28+8.97+10.07+9.33+12.11+8.19+21.50+6.85+6.75+6.86+6.42)/15 = 9.77. Therefore, the correct answer is (C) 9.77.

The Data Below Represent the Means from 15 Sample Control