Manufacturing and Product Development The left outside panel of an apartment-size, frost-free refrigerator is designed to have width 235 8 inches. Each hour, 10 such panels are randomly selected from...

Manufacturing and Product Development The left outside panel of an apartment-size, frost-free refrigerator is designed to have width 235 8 inches. Each hour, 10 such panels are randomly selected from the assembly line and carefully measured. If there is any evidence that the mean width is different from 23 inches, the assembly line is shut down for cleaning and inspection. Suppose the distribution of panel widths is normal and σ = 0.15.

a. During a specific hour of operation,
 = 23.7 inches. Should the assembly line be shut down? Use a = 0.05.

b. Using a 5 0.05, find the critical values in the x world. (Note: There are two critical values, because this is a two-sided hypothesis test.)