Executives of a supermarket chain are interested in the amount of time that customers spend in the stores during shopping trips. The mean shopping time,

, spent by customers at the supermarkets has been reported to be35

minutes, but executives hire a statistical consultant and ask her to determine whether it can be concluded that

is different from35

minutes.

To perform her statistical test, the consultant collects a random sample of shopping times at the supermarkets. She computes the mean of these times to be

42

minutes and the standard deviation of the times to be10

minutes.Based on this information, answer the questions below.

What are the null hypothesis (H

0

) and the alternative hypothesis (H

1

) that should be used for the test?

H

0

:

is?less thanless than or equal togreater thangreater than or equal tonot equal toequal to?421035

H

1

:

is?less thanless than or equal togreater thangreater than or equal tonot equal toequal to?421035

In the context of this test, what is a Type I error?

A Type I error is?rejectingfailing to rejectthe hypothesis that

is?less thanless than or equal togreater thangreater than or equal tonot equal toequal to?421035when, in fact,

is?less thanless than or equal togreater thangreater than or equal tonot equal toequal to?421035.

Suppose that the consultant decides not to reject the null hypothesis. What sort of error might she be making??Type IType II