You may need to use the appropriate appendix table or technology to answer this question. The following results are for independent random samples taken from two populations. Sample 1 = 20 Sample 2 = 30 X1 = 22.6 2 = 20.1 S1 = 2.9 52 = = 4.2 (a) What is the point estimate of the difference between the two population means? (Use X - X2.) (b) What is the degrees of freedom for the t distribution? (Round your answer down to the nearest integer.) (c) At 95% confidence, what is the margin of error? (Round your answer to one decimal place.) (d) What is the 95% confidence interval for the difference between the two population means? (Use X - X2. Round your answers to one decimal place.) to