22. More hypotheses. Write the null and alternative hypotheses to test each of the following situations.

a) A business magazine article reports that, in 1990, 35%

of CEOs had an MBA degree. Has the percentage changed?

b) Recently, 20% of cars of a certain model have needed costly transmission work after being driven between 50,000 and 100,000 miles. The car manufacturer hopes that the redesign of a transmission component has solved this problem.

c) A market researcher for a cola company decides to field test a new flavor soft drink, planning to market it only if he is sure that over 60% of the people like the flavor.