Partially Correct

Your answer is incorrect.

• (a) The null hypothesis: Your answer is incorrect.
• (a) The alternative hypothesis: Your answer is incorrect.
• (b) The degree of freedom: Your answer is incorrect.
• (c): Your answer is incorrect.
• (d): Your answer is incorrect.

As part of a staged rollout, a new email client was installed on some of the computers of a major company's customer service representatives (CSRs). These CSRs have complained to management saying that the new client is much worse than the old one. One of the company's performance analysts has been tasked with determining if on the busiest day of the year the mean time (in minutes) spent working on email for CSRs using the new email client is greater than the mean time (in minutes) spent working on email for CSRs using the old email client.

On the busiest day of the year, the performance analyst studies a random sample of

17

CSRs using the new email client and a random sample of

18

CSRs using the old email client. (These samples are chosen independently.) Each CSR records the amount of time (in minutes) they spend working on email. For the CSRs using the new email client, the sample mean is

180.4

with a sample variance of

144.1

.For the CSRs using the old email client, the sample mean is

159.5

with a sample variance of

2995.9

.

Assume that the populations of times are approximately normally distributed. Can the performance analyst conclude, at the

0.10

level of significance, that the population mean of the times spent working on email that day for CSRs using the new email client is greater than the population mean of the times spent working on email that day for CSRs using the old email client?