Question: After many years of teaching a statistics professor computed the
After many years of teaching, a statistics professor computed the variance of the marks on her final exam and found it to be σ2 = 250. She recently made changes to the way in which the final exam is marked and wondered whether this would result in a reduction in the variance. A random sample of this year’s final exam marks are listed here. Can the professor infer at the 10% significance level that the variance hasdecreased?
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