To decide whether two different types of steel have the same true average fracture toughness values, n specimens of each type are tested, yielding the following results:
Type.............. Sample Average............. Sample SD
1 ................................60.1........................ 1.0
2 ................................59.9........................1.0
Calculate the P-value for the appropriate two-sample z test, assuming that the data was based on n = 100. Then repeat the calculation for n = 400. Is the small P-value for n = 400 indicative of a difference that has practical significance? Would you have been satisfied with just a report of the P-value?