I have marks of year 2017 and 2018.

2017 mean score is 72.89 standard deviation in 2017 is 18.78678999 2018 mean score is 67.34 standard deviation in 2018 is 17.21293718

My question:

a. Confidence interval estimates for the mean/proportion

b. Confidence interval for the difference between two means. State the assumptions clearly

Mark Year 2017 Year 2018 50 50 71 64 57 86 82 68 89 80 77 86 97 78 65 66 63 71 90 73 73 65 50 82 79 62 50 84 63 50 98 79 83 64 80 95 78 77 52 67 95 50 62 66 76 96 80 82 94 72 94 77 96 57 72 62 83 84 61 91 58 72 66 72 94 28 79 42 61 46 97 28 77 43 63 44 87 74 76 86 51 86 3 35