Question 6.22: Four different coating formulations are tested to see if the...
Four different coating formulations are tested to see if they reduce the wear on cam gears to a value below 100 μm. The null hypothesis H_0: μ: ≥ 100 μm is tested for each formulation, and the results are
Formulation A: p = 0.37
Formulation B: p = 0.41
Formulation C: p = 0.005
Formulation D: p = 0.21
The operator suspects that formulation C may be effective, but he knows that the P-value of 0.005 is unreliable, because several tests have been performed. Use the Bonferroni adjustment to produce a reliable p-value.
Four tests were performed, so the Bonferroni adjustment yields P = (4)(0.005) = 0.02 for formulation C. So the evidence is reasonably strong that formulation C is in fact effective.