4. [-/8.33 Points] DETAILS ASWSBE14 10.E.009.MI. 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 x-22.6 x 20.1 5-2.1 2-4.8 (a) What is the point estimate of the difference between the two population means? (Use x, - x-) (b) What is the degrees of freedom for the t distribution? (Round your answer down to the nearest integer.) MY NOTES ASK YOUR TEACHER (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