Missing question: How many executives should be surveyed?
Solution:
Mean = 13 hours
SD = 3 hours
Confidence level = 95%
Mean viewing time within a quarter of an hour = 0.25 = 1.96*3/sqrt (N)
Where N = Sample population
N = {(1.96*3)/0.25}^2 = 553.19 ≈ 554
Therefore, 554 executives should be surveyed to yield such results.
Answer:
--- test statistic
--- p value
Conclusion: Fail to reject the null hypothesis.
Step-by-step explanation:
Given


--- Null hypothesis
---- Alternate hypothesis

Solving (a): The test statistic
This is calculated as:

So, we have:






Solving (b): The p value
This is calculated as:

So, we have:

Look up the z probability in the z score table. So, the expression becomes


Solving (c): With
, what is the conclusion based on the p value
We have:

In (b), we have:

By comparison:

i.e.

So, we fail to reject the null hypothesis.