For each problem below, test for the signifi -

cance of the difference in sample statistics using the fi ve-step model. (HINT: Remember to solve Formula 9.4 for before attempting to solve For mula 9.2. Also, in Formula 9.4, perform the mathematical operations in the proper sequence. First square each sample standard deviation, then divide by N 1, add the resultant values, and then find the square root of the sum.)

a. Sample 1 Sample 2 X —1 = 72.5 X —2 = 76.0 s1 = 14.3 s2 = 10.2 N1 = 136 N2 = 257 b.

Sample 1 Sample 2 X —1 = 107 X —2 = 103 s1 = 14 s2 = 17 N1 = 175 N2 = 200