The table shows the probabilities of people in Wales being in blood group O or in blood group A or in blood group AB. All people in Wales are in exactly one of the blood groups O, A, B or AB. There are 1200 students in Aled’s school. Aled’s school is in Wales. Work out an estimate for the number of pupils in Aled’s school who are in blood group AB.

3.17 scores on stats final. below are final exam scores of 20 introductory statistics students. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 57, 66, 69, 71, 72, 73, 74, 77, 78, 78, 79, 79, 81, 81, 82, 83, 83, 88, 89, 94 (a) the mean score is 77.7 points. with a standard deviation of 8.44 points. use this information to determine if the scores approximately follow the 68-95-99.7% rule. (b) do these data appear to follow a normal distribution? explain your reasoning using the graphs provided below.