Emma's On-the-Go, a large convenience store, has to decide where in the store to put its magazine rack. The manager at Emma's experiments with a selection of different locations, choosing a sample of days at each location. Each day, the manager records the amount of money brought in from the sale of magazines.
It's possible to test whether there is a difference in the mean daily sales for the different locations by doing a one-way, independent-samples ANOVA test. The variable of interest is the daily sales, in dollars, from magazines at Emma's. In the ANOVA test, the "groups" are the different locations, and the "samples" are the daily magazine sales actually examined by the manager.
The following ANOVA table gives a summary of such an ANOVA test. Fill in the missing cell in the table (rounded to two decimal places), and then answer the questions.
(Table set up below)
Source of
Variation/degrees of freedom/Sum of squares/mean of squares/ F statistic
Treatment 3 4777.5 1592.5 ?
between
groups
Error 192 71308.8 371.4
Within
Groups
Total 195 76086.3
How many days total wer sampled for the manager's experiment?
What is an unbiased estimate of this common population variance based on sample variances?
What is the p-value corresponding to the F statistic for the ANOVA test?
Using a 0.01 level of significance, is the a difference in the mean daily sales among the different locations?