For each conjecture, state the null and alternative hypotheses.
a. The average age of community college students is 24.6 years.
b. The average income of accountants is $51,497.
c. The average age of attorneys is greater than 25.4 years.
d. The average score of high school basketball games is less than 88.
e. The average pulse rate of male marathon runners is less than 70 beats per minute.
f. The average cost of a DVD player is $79.95.
g. The average weight loss for a sample of people who exercise 30 minutes per day for 6 weeks is 8.2 pounds.