The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stop watch to record the time they spent in line. The times recorded were as follows (in minutes) (mean = 114.15):
118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118

-What is the variance?
A)103
B)23.62
C)557.97
D)128.8
E)115

Question

The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stop watch to record the time they spent in line. The times recorded were as follows (in minutes) (mean = 114.15):
118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118

-What is the variance?
A)103
B)23.62
C)557.97
D)128.8
E)115

Quizplus · Accepted Answer

The variance is calculated by taking the average of the squared differences from the Mean. Here, the mean is given as 114.15. To find the variance, each value's difference from the mean is squared, those squared differences are summed, and then the sum is divided by the number of observations minus one (since this is a sample, not a population). The correct calculation leads to a variance of 557.97.

The Local Amusement Park Was Interested in the Average Wait