Zappos is an online retailer based in Nevada. One of their competitors, Amazon.com, would like to test the hypothesis that the average age of a Zappos employee is less than 36 years old. A random sample of 22 Zappos employees was found to have an average age of 33.9 years. Assume that the population standard deviation is 4.1 years. Zappos would like to set alpha = 0.05. The critical value is _______ and the null hypothesis should ______ :

Select one:

a.-1.645; be rejected.

b.1.645; be rejected.

c.1.96; not be rejected.

d.1.645; not be rejected.