For the following question(s): A school counselor claims that he has developed a technique to reduce prestudying procrastination in students. He has students time their procrastination for a week and uses this as a pretest (before)indicator of procrastination. Students then attend a workshop in which they are instructed to do a specific warming-up exercise for studying by focusing on a pleasant activity. For the next week, students again time their procrastination. The counselor then uses the time from this week as the posttest (after)measure.
-Suppose the counselor found the sum of squared deviations from the mean of the sample to be 135. Given that he tested 10 people, what would be the estimated population variance?
A)135/10 = 13.5
B)135/9 = 15.0
C)10/135 = .074
D)9/135 = .067

Question

Quizplus · Accepted Answer

To estimate the population variance, we use the formula S^2 = SS/n-1, where SS is the sum of squared deviations from the mean and n is the sample size. Here, SS = 135 and n = 10. Plugging these values into the formula gives S^2 = 135/9 = 15.0. Therefore, the estimated population variance is 15.0. Choice (A) is incorrect because it divides by 10 instead of 9. Choices (C) and (D) are incorrect because they do not use the formula for estimating the population variance.

For the Following Question(s): a School Counselor Claims That He