A manufacturing company wants to determine whether there is a difference between the variance of the number of units produced per day by one machine operator and the similar variance for another machine operator. The file P09_21.xlsx contains the number of units produced by operator 1 and operator 2, respectively, on each of 25 days. Note that these two sets of days are not necessarily the same, so you can assume that the two samples are independent of one another.
a. Identify the null and alternative hypotheses in this situation.
b. Do these sample data indicate a statistically significant difference at the 10% level? Explain your answer. With your conclusion, which possible error could you be making, a type I or type II error?
c. At which significance levels could you not reject the null hypothesis?
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