Author Question: According to R.L. Polk & Co, Americans held onto their new vehicles for an average of 71.4 ... (Read 60 times)

vicotolentino · **on:** Jun 24, 2018

According to R.L. Polk & Co, Americans held onto their new vehicles for an average of 71.4 months.

A random sample of 60 adults who recently sold their new vehicle was selected. Assuming the standard deviation for this population is 15.8 months, the standard error for this sample is ________.
A) 1.30
B) 2.04
C) 3.56
D) 5.92

Question 2

YouTube would like to test the hypothesis that the standard deviation for the length of an online video watched by a user is more than 2 minutes. A random sample of 21 people who watched online videos was selected.

The sample standard deviation for the length of the video was found to be 2.5 minutes. Using = 0.10, the critical value for this hypothesis test would be ________.A) 12.443
B) 28.412
C) 29.615
D) 30.813