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...

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 5 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?