The average number of cavities that thirty-year-old Americans have had in their lifetimes is 9. Do twenty-year-olds have fewer cavities? The data show the results of a survey of 16 twenty-year-olds 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 α = 0.01 level of significance? Write the hypothesis, give the test statistic and p-value. Write the decision about Ho and the 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 α = 0.10 level of significance? Write the hypothesis, give the test statistic and p-value. Write the decision about Ho and the 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 do not volunteer at the same rate as other students.