Please Show All of your Work! Complete 9 Problems
1. A poll is conducted with 1434 randomly selected U.S. adults. The poll showed that 72% of the
respondents support gun rights. The sample results are n = 1434 and
^ = 0.72. Find the
p
confidence Interval that corresponds to a 95% confidence interval.
^ + z α √ ^ ( 1− ^ ) / n
p
p
p
2
to
^ −z α √ ^ ( 1− ^ ) / n
p
p
p
2
2. A poll is conducted with 1845 randomly selected U.S. adults. The poll showed that 46% of the
respondents believe in cold fusion. The sample results are n = 1845 and
margin of Error that correspond to a 90% confidence interval.
E=
z α √ ^ ( 1− ^ ) /n
p
p
2
^ =0.46 .
p
Find the
3. The mean MPG of a mid-sized sedan is 24.6. If a hypothesis test is performed, how should you
interpret a decision that rejects the null hypothesis? Circle the correct answer.
a. There is sufficient evidence to support the claim μ=24.6 .
b. There is sufficient evidence to reject the claim μ=24.6 .
4. Suppose we are testing the following hypotheses:
H 0 : μ=25∧H 1 : μ>25. Determine the
nature of the hypothesis test.
5. Suppose we are testing the following hypotheses:
H 0 : μ=25∧H 1 : μ<25. Determine the
nature of the hypothesis test.
6. Suppose we are testing the following hypotheses:
H 0 : μ=25∧H 1 : μ ≠25. Determine the
nature of the hypothesis test.
7. For
^ H 0 : μ=20∧H 1 : μ<20.
A
30 and ∝=0.025 ?
^
A what is the critical value z for a sample with
^
A n=
8. For
^ H 0 : μ=20∧H 1 : μ<20.
A
^
A what is the critical value z for a sample with
^
A n=
10 and ∝=0.05 ?
9. Which of the following statements is true?
a. The level of significance, ∝ , is the maximum alternative allowable probability of
making a Type II error.
b. The level of significance, ∝ , is the minimum alternative allowable probability of
making a Type II error.
c. The level of significance, ∝ , is the maximum alternative allowable probability of
making a Type I error.
d. The level of significance, ∝ , is the minimum alternative allowable probability of
making a Type I error.
10. What is the critical value for a right-tailed test with
∝ = 0.01 of a large population?
11. The mean cost of a computer is $432. If a hypothesis test is performed, how should you
interpret a decision that supports the null hypothesis? Circle the correct answer.
a. There is sufficient evidence to support the claim μ=432 .
b. There is sufficient evidence to reject the claim μ=432 .
12. True or False: The degree of freedom is equal to the sample size (n).
