Having done poorly on a particular exam in a junior high school, 22 students decide to write the exam again to try and improve their mark. Results are given in the following table. Student Average Standard deviation Attempt 1 (A1) 22 58 3.4 Attempt 2 (A2) 22 63 4.1 Difference (d = A1 - A2) 22 -5.0 2.6 (a) Find a 98% confidence interval for the difference in mean scores between attempt 1 and attempt 2. (Round your answers to 4 decimal places, if needed.) (b) Based on this confidence interval, can we conclude there is a difference in mean scores between attempt 1 and attempt 2? O Yes, since the interval is completely below 0. O Yes, since the interval contains 0. O No, since the interval contains 0. O No, since the interval is completely below 0. Check