Download AP Statistics Review 8.4 – 8.6 Name Period ______ Formulas: On

AP Statistics Review 8.4 – 8.6
Formulas:
z=
Name _______________________________ Period _______
x - mx
s
t=
n
x - mx
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n
On word problems make sure to solve the problem and show your work (critical values, pvalues, test statistics, etc.)! Make sure to write your conclusions in full sentences and
address the original claim.
1. The mean starting salary for 65 college graduates was found to be $45,678. The standard
deviation of all starting salaries is $9,900. Using a 0.05 significance level, test the claim that the
mean starting salary for all college graduates is equal to $46,000.
2. The mean number of homeruns hit by 15 teams last year was 152. Assume that the standard
deviation of all of the teams in the league is 6.4 homeruns. Use a 0.05 significance level to test the
claim that the mean number of homeruns hit by all teams will have a mean of more than 160.
Assume that the data has a normal distribution.
3. Use your calc to find the P-value given the test statistic. (Round to 4 sign. decimal places)
a. left-tailed test; test statistic is z = -1.994 ______________
b. right-tailed test; test statistic is t = 2.723, n = 50 _______________
 c. left-tailed test; test statistic is t = -5.217, n = 150 ______________
 d. two-tailed test; test statistic is z = -3.245
_________________
 e. two-tailed test; test statistic is t = 1.44, n = 76
______________
f. H1: 𝜎 ≠ 2.00, 𝛼 = 0.05, n = 10, 𝜒 2 = 20.250 _________________
g. H1: 𝜎 > 15, 𝛼 = 0.05, n = 5, 𝜒 2 = 16.000 _________________
4. A researcher claims that adults spend more than 18 hours per week watching TV. A sample of
10 adults finds that the mean is 25.7 hours with a standard deviation of 9.04 hours. Use a 0.05
significance level to test the claim that adults spend an average of more than 18 hours watching TV.
Assume that the data has a normal distribution.
5. A sample of 15 girls found that they own an average of 8.7 pairs of shoes with a standard
deviation of 0.85 pairs. Use a 0.05 significance level to test the claim that girls own less than an
average of 10 pairs of shoes. Assume that the data follows a normal distribution.
6. A group of researchers did a study of pregnant cocaine-dependent women. A sample of 50
cocaine-dependent women showed that the mean birth weight of their babies was 2,971 grams and
had a standard deviation of 410 grams. Use a 0.01 significance level to test the claim that the birth
weights of the babies delivered to cocaine-dependent mothers had a standard deviation of less than
447.2 grams. Assume that the data has a normal distribution.
7. At Jefferson Valley Bank customers enter a single waiting line that feeds three teller windows.
For a sample of 100 customers, it was found that the mean wait time was 7.51 minutes and that
the standard deviation was 0.49 minutes. Use a significance level of 0.10 to test the claim that the
standard deviation of the wait times at the same bank will be 1.7 minutes. Assume that the data is
normal.