Answer
a. $H_0$: µ $\geq$ 27 years, $H_1$: µ < 27 years
The null hypothesis specifies that the average age of first year medical school students is at least is 27 years., and the alternative hypothesis states that it will be less than 27 years. The test is a left-tailed test, since the interest is in the average age of first year medical school students that is less than 27 years.
b. $H_0$: µ = 4.71 scores , $H_1$: µ $\ne$ 4.71 scores
The null hypothesis specifies that the average experience (in seasons) for an NBA player is 4.71 scores., and the alternative hypothesis states that it will be different. The test is a two-tailed test, since the possible average experience (in seasons) for an NBA player could be less than or more than 4.71 scores.
c. $H_0$: µ = 36 times , $H_1$: µ > 36 times
The null hypothesis is that the average number of monthly visits on the Internet by a person at home is equal to 36 times, and the alternative hypothesis states that the average number of monthly visits on the Internet by a person at home is greater than 36 times The test is a right-tailed test, since the interest is in the frequency of visits that is greater than 36 times.
d. $H_0$: µ = 79.95 dollars , $H_1$: µ $\ne$ 79.95 dollars
The null hypothesis is that the average cost of a DVD player is 79.95 dollars, , and the alternative hypothesis states that it will be different. The test is a two-tailed test, since the possible average cost of a DVD player could be less than or more than 79.95 dollars.
e. $H_0$: µ = 8.2 pounds , $H_1$: µ $\ne$ 8.2 pounds
The null hypothesis is that the average weight loss for a sample of people who exercise 30 minutes is 8.2 pounds, and the alternative hypothesis states that it will be different. The test is a two-tailed test, since the average weight loss for a sample of people who exercise 30 minutes could be less than or more than 8.2 pounds.
