AP Statistics Quiz 9.1AB-1.pdf - Quiz 9.1A AP Statistics...

© 2011 BFW Publishers The Practice of Statistics, 4/e- Chapter 9 413
Quiz 9.1A AP Statistics Name:
1. For each of the following settings, define the parameter of interest and write the appropriate
null and alternative hypotheses for the test that is described.
(a) The mean weight of loaves of bread produced at the bakery where you work is supposed
to be one pound. You are the supervisor of quality control at the bakery, and you are
concerned that new personnel are producing loaves that have a mean weight of more than
one pound.
(b) According to the Humane Society, 33% of households in the United States own at least
one cat. You are interested in determining whether the proportion of households of the
students at your school that own at least one cat is different from the national proportion.
2. Consider the bakery problem in question 1(a). Suppose you weigh an SRS of bread loaves
and find that the mean weight is 1.025 pounds, which yields a P -value of 0.086.
(a) Interpret the P -value in the context of the problem.
(b) What conclusion would you draw at the °D = 0.05 level? At the °D = 0.10 level?

414 The Practice of Statistics, 4/e- Chapter 9 © 2011 BFW Publishers