Answer Happy

A CEO of a certain company analyzed the amount of time (in minutes) that workers spend weekly on disinfecting their working environment, depending on the type of work performed. The data collected for a random sample is summarized in the following table: Manager Accountant Other HR specialist 20 10 20 20 category average time variance of time (unbiased estimator) number of observations 16 17 15 17 4 6 6 4 We assume that the analyzed variable follows a normal distribution. • The CEO wishes to perform an ANOVA to verify the null hypothesis that the average time spent on disinfecting is the same for all categories of workers. The value of the appropriate test statistic amounts to , the critical region of the test has the form ), so at a significance level of 0.01 we the null hypothesis. • If the average times for all categories decreased twofold, the value of the test statistic would If the variances for all categories increased twofold, the value of the test statistic would If the sample sizes of all categories of workers decreased twofold, the value of the test statistic would { Note. When providing numerical values, please approximate to two decimal digits. When providing the critical region of the test, please use the notation "-infinity" and "+infinity" for -- and too, respectively,