Author Question: Suppose that vehicle speeds at an interstate location have a normal distribution with a mean equal ... (Read 59 times)

Haya94 · **on:** Jul 24, 2018

Suppose that vehicle speeds at an interstate location have a normal distribution with a mean equal to 70 mph and standard deviation equal to 8 mph. What is the z-score for a speed of 64 mph?
a. -6
b. -0.75
c. +0.75
d. +6

Question 2

A 95 confidence interval for the proportion of women that has ever dozed off while driving is 0.07 to 0.14 . For men, a 95 confidence interval for the proportion that has ever dozed off while driving is 0.19 to 0.25 . Assume both intervals were computed using large random samples. What conclusion can be made about the population proportions that have dozed off while driving?
a. It is reasonable to conclude that there is a difference between men and women.
b. It is not reasonable to conclude that there is a difference between men and women.
c. It is reasonable to conclude that there is a difference of 0.05 between men and women.
d. No conclusion is possible because we don't know the margin of error.