The following data represent the scores of a sample of 50 students on a statistics exam. The mean score is $\bar { x } = 80.3$, and the standard deviation is $s = 11.37$.
$\begin{array} { l l l l l l l l l l } 49 & 51 & 59 & 63 & 66 & 68 & 68 & 69 & 70 & 71 \ 71 & 71 & 73 & 74 & 76 & 76 & 76 & 77 & 78 & 79 \ 79 & 79 & 79 & 80 & 80 & 82 & 83 & 83 & 83 & 85 \ 85 & 86 & 86 & 88 & 88 & 88 & 88 & 89 & 89 & 89 \ 90 & 91 & 92 & 92 & 93 & 95 & 96 & 97 & 97 & 98 \end{array}$
What percentage of the scores fall in each of the intervals $\bar { x } \pm s , \bar { x } \pm 2 s$, and $\bar { x } \pm 3 s$ ? Based on these percentages, do you believe that the distribution of scores is approximately normal? Explain.

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The Answer of The following data represent the scores of a sample of 50 students on a statistics exam. The mean score is $\bar { x } = 80.3$, and the standard deviation is $s = 11.37$.
$\begin{array} { l l l l l l l l l l } 49 & 51 & 59 & 63 & 66 & 68 & 68 & 69 & 70 & 71 \ 71 & 71 & 73 & 74 & 76 & 76 & 76 & 77 & 78 & 79 \ 79 & 79 & 79 & 80 & 80 & 82 & 83 & 83 & 83 & 85 \ 85 & 86 & 86 & 88 & 88 & 88 & 88 & 89 & 89 & 89 \ 90 & 91 & 92 & 92 & 93 & 95 & 96 & 97 & 97 & 98 \end{array}$
What percentage of the scores fall in each of the intervals $\bar { x } \pm s , \bar { x } \pm 2 s$, and $\bar { x } \pm 3 s$ ? Based on these percentages, do you believe that the distribution of scores is approximately normal? Explain.

The Following Data Represent the Scores of a Sample of 50