Question

A researcher collated data on Americans’ leisure time activities. She found the mean number of hours spent watching television each weekday to be 2.7 hours with a standard deviation of 0.4 hours. Jonathan believes that his football team buddies watch less television than the average American. He gathered data from 15 football teammates and found the mean to be 2.3. Which of the following shows the correct z-statistic for this situation?
a. -3.87
b. -0.26
c. 3.22
d. 5.22

Answer 1

Z-score = (2.3 - 2.7)/(0.4/√15) = -0.4/0.1033 = -3.87

Answer 2

Answer:

Option A

Step-by-step explanation:

Let X be the the mean number of hours spent watching television each weekday by Americans during their leisure time

X is N(2.7, 0.4)

Jonathan claims that A group of 15 football teammates have mean say Y less than X

Difference in means = 2.3-2.7 = -0.4

Std error of sample = 0.4/]sqrt 15=0.1033

Test statistic = difference in means /Std error

==3.87

Option A is right