11-26. Independent random samples of sizes nX = 8 and nY = 10 were extracted from normal populations having unknown means. If it is known that σ2X

=

2.5 and σ2Y

= 4.8, find a 95% confidence interval for μX − μY.

Sample 1: 3, 8, 6, 5, 10, 7, 7, 6 Sample 2: 1, 5, 8, 8, 6, 7, 6, 9, 4, 3 What is the 95% confidence interval for μX − μY if the population variances are unknown?