Use the following information to answer questions (1) - (5). Feature movie lengths (in hours) were measured for all movies shown in the past year in the U.S. The mean length of all feature length movies shown was 1.80 hours with a standard deviation of 0.15 hours. Suppose the length of a random sample of 20 movies was recorded from all movies released this year. The mean length of the feature length movies was found to be 1.72 hours with a standard
deviation of 0.18 hours.
-What is the standard error for the estimated mean feature length movie time of the 20 randomly selected movies? Round to the nearest thousandth.
A)0.356
B)0.040
C)0.055
D)0.034

Question

Quizplus · Accepted Answer

The standard error of the mean (SEM) is calculated using the formula SEM = s / √n, where s is the standard deviation of the sample and n is the sample size. Here, s = 0.18 hours and n = 20. Thus, SEM = 0.18 / √20 = 0.0402, which rounds to 0.040.

Use the Following Information to Answer Questions (1) - (5)