Question

An average department store sells 250 men's suits per year. The men's suit departments at a particular national chain of stores claim they sell more than the industry average. In 45 of their stores, they sold, on the average, 270 suits per year with a population standard deviation of 50. What is the test value for their claim?

Answer 1

The null and alternate hypothesis are:

H0:

Ha:

Let the level of significance be 5%.

The test statistic is given by:

Since this is a right-tailed test, so the p-value is given by:

Since p-value is less than 0.05, so we have sufficient evidence to reject the null hypothesis H0.

Thus we can conclude that .