A shoe salesman wishes to check the validity of his supplier's claim that the average length of the adult male foot is 9.34 in.He randomly samples 35 customers and finds their average foot length to be 9.01 in.The standard deviation of foot length is known to be 0.75 in.What would be the critical value and decision for this test if the salesman thinks the supplier's claim is too high? (Use α = 0.01.)
A) -2.3263; fail to reject H₀
B) -1.2816; reject H₀
C) -2.3263; reject H₀
D) -1.2816; fail to reject H₀

Question

Quizplus · Accepted Answer

The critical value for a one-tailed test at α = 0.01 is -2.3263. Since the salesman believes the supplier's claim is too high, he is conducting a left-tailed test. If the calculated test statistic falls to the left of -2.3263, he would reject H₀, indicating that the average foot length is significantly less than 9.34 in.

A Shoe Salesman Wishes to Check the Validity of His