29. The amount of shaft wear (.0001 in.) after a xed mileage was determined for each of n  8 internal combustion engines having copper lead as a bearing material, resulting in and s  1.25.

a. Assuming that the distribution of shaft wear is normal with mean m, use the t test at level .05 to test H0: m  3.50 versus Ha: m 3.50.

b. Using s  1.25, what is the type II error probability b(m) of the test for the alternative m 

4.00?