Name ________________________ Date _____________
AP Statistics Schwimmer
Chapter 11 Review #2 ( oops!)
Part I. Multiple Choice. Circle the number corresponding to the best answer.
1. A significance test was performed to test the null hypothesisH 0µ = 2 versus the alternative
H aµ ≠ 2. The test statistic is z = 1.40. The P-value for this test is approximately
(1) 0.16 P ( < −1.4 or z >1.4 = )P z >1(4 =.16 )
2. An appropriate 95% confidence interval for µ has been calculated as (–0.73, 1.92) based on n =
15 observations from a population with a Normal distribution. The hypotheses of interest are
H 0µ = 0 versus H :µ a 0. Based on this confidence interval,
If the interval contains µ 0
(1) we should reject H a0 the α = 0.05 level of significance.
we do not have sufficient
(2) we should not reject H 0t the α = 0.05 level of significance. evidence to reject the null.
(3) we should reject H at the α = 0.10 level of significance.
(4) we should not reject H 0t the α = 0.10 level of significance.
(5) we cannot perform the required test since we do not know the value of the test statistic.
3. To increase the power of a significance test, you could
(1) use a two-tailed test instead of a one-tailed test.
(2) decrease the size of your sample.
(3) find a way to increase the population standard deviation σ.
(4) increase the significance levelα.
(5) perform the test many times.
4. A radio show runs a phone-in survey each morning. One morning the show asked its listeners
whether they would prefer Congress or the president to set policy for the nation. The majority of
those phoning in their responses answered “Congress,” and the station reported the results as
statistically significant. We may safely conclude that
(1) there is deep discontent in the nation with the president.
(2) it is unlikely that, if all Americans were asked their opinion, the result would differ from that
obtained in the poll.
(3) there is strong evidence that the majority of Americans prefer Congress to set national policy.
(4) very few people other than the majority of those phoning in their responses prefer Congress
to set policy for the nation.
(5) the poll result may be biased due to the method of data collection. 5. The average growth of a certain variety of pine tree is 10.1 inches in three years. A biologist
claims that a new variety will have a greater three-year growth. A random sample of 25 of the
new variety has an average three-year growth of 10.8 inches and a standard deviation of 2.1
inches. The appropriate null and alternative hypotheses to test the biologist’s claim are
(1) H : µ =10.8;H :µ >10.8
(2) H : µ =10.8;H :µ ≠10.8
(3) H : µ =10.1;H : µ >10.1
(4) H :0µ =10.1;H : µ