The test scores of 20 students on a 100-point test were recorded. 72 91 92 | 85 73 75 84 84 77 58 83 88 65 61 73 79 67 64 74 86 (a) Create a stem and leaf plot for the data. (Enter numbers from smallest to largest separated by spaces. Enter NONE for stems with no values.) stem leaf 5 6 7 8 Can you reasonably assume that these test scores have been selected from a normal population? O Yes, the stem and leaf plot indicates that this is a reasonable assumption. O No, the stem and leaf plot indicates that this is not a reasonable assumption. (b) Calculate the mean and standard deviation of the scores. (Round your standard deviation to three decimal places.) mean standard deviation (c) If these students can be considered a random sample from the population of all students, find a 95% confidence interval for the average test score in the population. (Round your answers to three decimal places.) to