The deflection temperature under load for two different types of plastic pipe is being investigated. Two random samples of 15 pipe specimens are tested, and the deflection temperatures observed are as follows (in °F):


Type 1: 206, 188, 205, 187, 194, 193, 207, 185, 189, 213, 192, 210, 194, 178, 205
Type 2: 177, 197, 206, 201, 180, 176, 185, 200, 197, 192, 198, 188, 189, 203, 192







(a) Do the data support the claim that the deflection temperature under load for type 1 pipe exceeds that of type 2? In reaching your conclusions, use a = 0.05. Calculate a P-value.

(b) If the mean deflection temperature for type 1 pipe exceeds that of type 2 by as much as 5°F, it is important to detect this difference with probability at least 0.90. Is the choice of n1 = n2 = 15 adequate? Use a = 0.05.