5) The average number of cavities that thirty-year-old Americans have had in their lifetimes is 9. Do
twenty-year-old have fewer cavities? The data show the results of a survey of 16 twenty-year-old who
were asked how many cavities they have had. Assume that the distribution of the population is normal.
11, 8, 5, 6, 10, 9, 6, 9, 11, 9, 6, 10, 11, 7, 6, 11
What can be concluded at the $\alpha = 0.01$ level of significance? Write hypothesis, give test stat and p-value.
Write decision about H0 and conclusion about the claim.
6) 19% of all college students volunteer their time. Is the percentage of college students who are
volunteers different for students receiving financial aid? Of the 350 randomly selected students who
receive financial aid, 53 of them volunteered their time. What can be concluded at the $\alpha = 0.10$ level of
significance? Write hypothesis, give test stat and p-value. Write decision about H0 and conclusion about
the claim.
Select the correct conclusion below:
a) Students who receive financial aid volunteer as much as the other students.
b) Students who receive financial aid does not volunteer at the same rate as other students.
