2 Section 9.4 #14abc & Section 9.3 #8
9.4
14. Confidence in banks: A poll conducted by the General Social Survey asked a random sample of
1325 adults in the United States how much confidence they had in banks and other financial institutions.
A total of 149 adults said that they had a great deal of confidence. An economist claims that less than
15% of U.S. adults have a great deal of confidence in banks.
a. State the appropriate null and alternate hypotheses.
b. Compute the test statistic š§.
c. Using š¼=0.05, can you conclude that the executiveās claim is true?
9.3
8. Fill in each blank with the appropriate word or phrase.
The number of degrees of freedom for the studentās t-test of a population mean is always 1 less than
the ______blank.