15.61 Dorris owns a homemade soymilk business and is looking for a machine that can produce the most soymilk within an hour. She collected 25 observations and measured the quantity of soymilk produced within an hour (in liters) by four different machines. From the data, she determined that the sum of squares of soymilk quantity produced within an hour between the four machines is 3632.91, and the sum of squares of soymilk quantity produced within brands is 6805.12.

a. Prepare the complete analysis of variance table.

b. Test the null hypothesis of equality of the four machines at 1% significance level.