Question

A professional employee in a large corporation receives an average of μ = 42.7 e-mails per day. Most of these e-mails are from other employees in the company. Because of the large number of e-mails, employees find themselves distracted and are unable to concentrate when they return to their tasks. In an effort to reduce distraction caused by such interruptions, one company established a priority list that all employees were to use before sending an e-mail. One month after the new priority list was put into place, a random sample of 38 employees showed that they were receiving an average of x = 35.3 e-mails per day. The computer server through which the e-mails are routed showed that σ = 19.6. Has the new policy had any effect? Use a 5% level of significance to test the claim that there has been a change (either way) in the average number of e-mails received per day per employee. What is the value of the test statistic?

Select one:

a. 2.327

b. -2.327

c. 0.061

d. 0.378

e. -0.061

Answer 1

Solution :

Given that ,

= 35.3

= 42.7

= 19.6

n = 38

Test statistic = z

= ( - ) / / n

= (35.3 - 42.7) / 19.6 / 38

= -2.327

Test statistic = -2.327

b)