Download 8.1-8.2 Review Sheet

Statistics
Name _____________________
8.1-8.2 Review
Date _______
Directions: Complete ALL problems. Show your Work.
In Exercises 1- 3, assume that a hypothesis test of the given claim will be conducted.
a.
Express the claim in symbolic form.
b.
Identify the null hypotheses 𝐻0
c.
Identify the alternative hypothesis 𝐻1
d.
Identify the test as being two-tailed, left-tailed, or right-tailed.
1. The mean time required for the undergraduates to earn a bachelor’s degree is greater
than 5 years.
2. The mean annual income of self-employed doctors is $191,000.
3. The proportion of college graduates who obtain a job after graduation at least 62%.
4. Find the critical value(s) for the given conditions. Assume that the normal distribution
applies, so Table A-2 can be used. Also, draw a graph showing the critical value and
critical region.
Right-tailed test; 𝛼 = 0.02
5. Identify the claim, null hypothesis, alternative hypothesis symbolically, suggested by the
given conclusions.
a.
There is sufficient evidence to support the claim that the mean age of college
professors is greater than 30 years.
b.
There is not sufficient evidence to support the claim that the standard
deviation for the weight of quarters is less than 5g.
c.
There is sufficient evidence to warrant rejection of the claim that proportion of
adult men who smoke is different from .56.
6. The claim is that the proportion of choking deaths of children attributable to balloons is
more than 0.25 and the sample statistics include 𝑛 = 400 choking deaths of children with
29.0% of them attributable to balloons.
a. State the null and alternative hypotheses.
b. Calculate the test statistic. Use 𝑧 =
𝑝̂−𝑝
𝑝𝑞
√𝑛
c. Calculate the 𝑃 − 𝑣𝑎𝑙𝑢𝑒.
d. What is the null decision? Explain.
e. What do you conclude about the proportion of choking deaths of children
attributable to balloons?