1. Twenty-five seniors from a large metropolitan area
school district volunteer to allow their Math SAT test scores to be
used in a study. These 25 seniors had a mean Math SAT score of =
450. Suppose we know that the standard deviation of the population
of Math SAT scores for seniors in the district is σ = 100. Assuming
the population of Math SAT scores for seniors in the district is
approximately Normally distributed, a 90% confidence interval for
the mean Math SAT score μ for the population of seniors computed
from these data is:

a. 450 ± 39.2.
b. not trustworthy.

2. If I wanted the margin of error for the 95%
confidence interval to be 1 inch, I should select a simple random
sample of size: (assume the population standard deviation =
2.415)

b. 23.
c. 39.

3. The Survey of Study Habits and Attitudes (SSHA) is a
psychological test that measures the motivation, attitudes, and
study habits of college students. Scores range from 0 to 200 and
follow (approximately) a Normal distribution, with a
mean of 110 and standard deviation σ = 20.
You suspect that incoming freshman has a
mean μ, which is different from 110 because they are often excited
yet anxious about entering college. To verify your suspicion, you
test the hypotheses
H0: μ = 110, Ha: μ 110
You give the SSHA to 50 students who are incoming
freshman and find their mean score.
The P-value of the test of the null hypothesis is the:

a. probability, assuming the null hypothesis is true, that the
test statistic will take a value at least as extreme as that
actually observed.
b. probability, assuming the null hypothesis is false, that the
test statistic will take a value at least as extreme as that
actually observed.

c. probability the null hypothesis is true.