Consider the following data drawn independently from normally distributed populations: (You may find it useful to reference the appropriate table: z table or ttable) x1 --8.3 $128.0 "118 x2 -17.5 2 $2' - 8.7 = 18 a. Construct the 95% confidence interval for the difference between the population means. Assume the population variances are unknown but equal. (Round final answers to 2 decimal places.) Confidence interval is to b. Specify the competing hypotheses in order to determine whether or not the population means differ. Ho1 -21 - - =0; HA M1120 Ho M1 20; HA 1 - 2 < 0 HO: 1 - 20; HA 1 - 2 > 0 c. Using the confidence interval from part a, can you reject the null hypothesis? Yes, since the confidence interval includes the hypothesized value of 0. O No, since the confidence interval includes the hypothesized value of O. Yes, since the confidence interval does not include the hypothesized value of 0. O No, since the confidence interval does not include the hypothesized value of 0. d. Interpret the results at = 0.05. We conclude that population mean 1 is greater than population mean 2. We cannot conclude that population mean 1 is greater than population mean 2. O We conclude that the population means differ. We cannot conclude that the population means differ.