Write the null and alternative hypotheses you would use to test each of the situations in parts (a) through (c).
(a) A prime minister is concerned about his "negatives," that is, the percentage of the country's residents who express disapproval of his job performance. His political committee pays for a series of TV ads, hoping that they can keep the negatives below 35%. They will use follow-up polling to assess the ads' effectiveness. Let p be the proportion of the country's residents who express disapproval of the prime minister's performance.
H0: p = 0.35
HA: p < 0.35
(b) Is an eight-sided die fair? Let p represent the probability of the die landing on any particular side.
H0: p = 1/8
HA: p ≠ 1/8
(c) Only about 30% of people who try to stop abusing alcohol succeed. Sellers of a motivational tape claim that listening to the recorded messages can help people succeed. Let p be the proportion of people who try to stop abusing alcohol and succeed.
H0: p = 0.30
HA: p > 0.30