Canidae Corporation, based in San Luis Obispo, California, is a producer of pet food. One of its products is Felidae cat food. The Chicken and Rice Cat and Kitten Formula is a dry cat food that comes in various sizes. Canidae guarantees that 32% of this cat food is crude protein. In the 6.6-pound (3-kilogram)

size, this would indicate that 2.11 pounds would be crude protein. Of course, these figures are averages.

The amount of crude protein varies with each sack of cat food. The file entitled Catfood contains the amounts of crude protein found in sacks randomly sampled from the production line. Assume the amount of crude protein in the 6.6-pound size is normally distributed.

a. If Canidae wishes to have the weight of crude protein sacks rounded off to 2.11 pounds, determine the standard deviation of the weight of crude protein. (Hint: Recall the relationship between the standard deviation and the range of a normal distribution used in the sample-size calculations in the confidence interval for a population mean.)

b. Using your result in part

a, conduct a hypothesis test to determine if the standard deviation of the weight of crude protein in the 6.6-pound sack of Felidae cat food is too large to meet Canidae’s wishes. Use a significance level of 0.01.