In each of the following situations, is the alternative hypothesis one-sided or two-sided? What are the hypotheses?

a) A college dining service wants to know if students prefer plastic or metal cutlery. They conduct a survey to find out.

b) In recent years, 10% of college juniors have applied for study abroad. The dean s office conducts a survey to see if that s changed this year.

c) A pharmaceutical company conducts a clinical trial to see if more patients who take a new drug experience headache relief than the 22% who claimed relief after taking the placebo.

d) At a small computer peripherals company, only 60% of the hard drives produced passed all their performance tests the first time. Management recently invested a lot of resources into the production system and now conducts a test to see if it helped.