15.55 Different formulation of laundry detergents show different cleaning effects, and most laundry detergent brands are reformulated at least once a year. A manufacturer has reformulated its laundry detergent and is determining the selling price per liter for the new product launch. Before making a decision, the manufacturer collected nine selling prices for each of the five different types of reformulated detergents from the market. The result showed that the sum of squares selling price is 137.7529, and the sum of squares selling price within the same formulation is 228.5329. The manufacturer then compares the results to see if there are any differences in the average selling price per liter for the reformulated detergents.

a. Use the information provided to prepare the analysis of variance table.

b. Test the null hypothesis that the population mean selling price per liter are the same for all the five different formulations.