The average sales per store of ABC Inc.’s best-selling product in a supermarket chain
was $15,000. A random sample of 80 stores selected from the chain shows that
the average sales per store is $14,300 with a sample standard deviation of $8,000. We wish
to determine if the average sales per store this year is less than $15,000.
State the null and alternative hypotheses to be tested. (
Compute the test statistic. (