Question: A billiards parlor in a small town is open just 4 days per week-Thursday through Sunday. Revenues vary considerably from day to day and week to week, so the owner is not sure whether some days of the week are more profitable than others. He takes random samples of 5 Thursdays, 5 Fridays, 5 Saturdays, and 5 Sundays from last year's records and lists the revenues for these 20 days. His bookkeeper finds the average revenue for each of the four samples, and then calculates . The results are shown in the following table. The value of the came out to be 2,890,000.
Assume that the revenues for each day of the week are normally distributed and that the standard deviations are equal for all four populations. At the 1% level of significance, can you conclude that the mean revenue is the same for each of the four days of the week?