EXAMPLE 6.26 The Power to Detect Departure from Target

CASE 6.1 Case 6.1 considered the following competing hypotheses:

In Example 6.13 (page 317), we learned that for the filling process. Suppose that the bottler Bestea wishes to conduct tests of the filling process mean at a 1% level of significance. Assume, as in Example 6.13, that 20 bottles are randomly chosen for inspection. Bestea’s operations personnel wish to detect a 1-ml change in mean fill amount, either in terms of underfilling or overfilling. Does a sample of 20 bottles provide sufficient power?