Question: Public Health and Nutrition Cast iron is an extremely durable cookware material, good for searing and blackening foods. However, a cast-iron pan, for example, can be full of bacteria and can lend unwanted flavors to food. A company trying to promote alternative ceramic cookware asked members of a community to bring their favorite cast-iron cookware to their store for bacteria testing. The company manager claimed that at least 60% of all cast-iron cookware contains harmful bacteria. A random sample of 120 pans was selected, and 57 were found to contain harmful bacteria.
a. Is there any evidence to refute the manager's claim? Use a = 0.01.
b. Find the p value associated with this hypothesis test.
c. Do you believe the sample is really random? Why or why not?