STT 231 EXAM 2 QUESTIONS AND
ANSWERS ALL CORRECT
What percentage of books in this library contain fewer than 300 pages?
A) z-interval for a proportion, π
B) z-test for a proportion, π
C) t-interval for a mean, μ
D) t-test for a mean, μ - Answer- A) z-interval for a proportion, π
Suppose you take a random sample of 100 books from a large library. Indicate the
appropriate inference procedure
How many pages, on average, are contained in a book from this library?
A) z-interval for a proportion, π
B) z-test for a proportion, π
C) t-interval for a mean, μ
D) t-test for a mean, μ - Answer- C) t-interval for a mean, μ
Suppose you take a random sample of 100 books from a large library. Indicate the
appropriate inference procedure
What percentage of books in this library have been borrowed at least once in the past
10 years?
A) z-interval for a proportion, π
B) z-test for a proportion, π
C) t-interval for a mean, μ
D) t-test for a mean, μ - Answer- A) z-interval for a proportion, π
How does sample size influence the estimated effect size? - Answer- No effect
How does sample size influence degrees of freedom? - Answer- increase in sample
size, increase in degrees of freedom
How does sample size effect the value of the test statistic "t"? - Answer- increase in
sample size, increase in test statistic
How does sample size influence the p-value? - Answer- as sample size increases, p-
value decreases
How does sample size influence MoE of your confidence interval? - Answer- sample
size increases, MoE of CI decreases
ANSWERS ALL CORRECT
What percentage of books in this library contain fewer than 300 pages?
A) z-interval for a proportion, π
B) z-test for a proportion, π
C) t-interval for a mean, μ
D) t-test for a mean, μ - Answer- A) z-interval for a proportion, π
Suppose you take a random sample of 100 books from a large library. Indicate the
appropriate inference procedure
How many pages, on average, are contained in a book from this library?
A) z-interval for a proportion, π
B) z-test for a proportion, π
C) t-interval for a mean, μ
D) t-test for a mean, μ - Answer- C) t-interval for a mean, μ
Suppose you take a random sample of 100 books from a large library. Indicate the
appropriate inference procedure
What percentage of books in this library have been borrowed at least once in the past
10 years?
A) z-interval for a proportion, π
B) z-test for a proportion, π
C) t-interval for a mean, μ
D) t-test for a mean, μ - Answer- A) z-interval for a proportion, π
How does sample size influence the estimated effect size? - Answer- No effect
How does sample size influence degrees of freedom? - Answer- increase in sample
size, increase in degrees of freedom
How does sample size effect the value of the test statistic "t"? - Answer- increase in
sample size, increase in test statistic
How does sample size influence the p-value? - Answer- as sample size increases, p-
value decreases
How does sample size influence MoE of your confidence interval? - Answer- sample
size increases, MoE of CI decreases
