Two random samples were selected independently from populations having normal distributions. The following statistics were extracted from the samples x1 = 42.3 x2 = 32.4 If sigma1 = 3 and sigma2 = 2 and the sample sizes are n1 = 50 and n2 = 50, calculate a 95% confidence interval for the difference between the two population means. If sigma1 = sigma2, s1 = 3, and s2 = 2, and the sample sizes are n1 = 10 and n2 = 10, calculate a 95% confidence interval for the difference between the two population means. If sigma1 sigma2, S1 = 3, and s2 = 2, and the sample sizes are n1 = 10 and n2= 10, calculate a 95% confidence interval for the difference between the two population means