Consider the following results for independent random samples taken from two populations. Sample 1 Sample 2 711 = 20 m = 40 1 = 22.1 $2 = 20.6 91 = 2.1 52 =4.7 a. What is the point estimate of the difference between the two population means (to 1 decimal)? 1.5 b. What is the degrees of freedom for the t distribution (round the answer to the previous whole number)? 58 C. At 95% confidence, what is the margin of error (to 1 decimal)? 23.4 d. What is the 95% confidence interval for the difference between the two population means (to 1 decimal and enter negative value as negative number)