Agrcup of 3 students were given the same standardized test twice to see whether retaking the test affected the score. The table gives the score differences for the 8 students. Use the paired t-interval procedure to determine a 98% condence interval for the difference between the mean scores on the rst test and the second test (retake). (Note: a: 10 and sd = 55.81.) The 98% condence interval is from to -. (Round to two decimal places as needed.)