Exam scores of 40 students in a statistics class are shown.
(a) Estimate the mean and standard deviation from the sample.
(b) Assuming that the data are from a normal distribution, de ne bins by using method 3 (equal expected frequencies). Use 8 bins.
(c) Set up an Excel worksheet for your chi-square calculations, with a column showing the expected frequency for each bin (they must add to 40).
(d) Tabulate the observed frequency for each bin and record it in the next column.
(e) Carry out the chi-square test, using α = .05. Can you reject the hypothesis that the exam scores came from a normal population?

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