Question

A soft-drink machine is designed to discharge, when operating properly, at most 20 ounces of beverage per cup with a standard deviation of 2.1 ounces. To check the machine reliability, a random sample of 25 cupfuls is selected. Compute the power of the test if the true (actual) population average amount dispensed is 21.6 ounces per cup. Use   .

Please show work.

Answer 1

Solution :

= 20

=21.6

S =2.1

n = 25

This is the left tailed test .

The null and alternative hypothesis is ,

H0 :    = 20

Ha : < 20

Test statistic = t

= ( - ) / S / n

= (21.6-20) / 2.1 / 25

= 3.81

Test statistic = t =3.81