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1) A tire manufacturer guarantees that the mean life of a certain
type of tire is at least 30,000 miles. Write the null hypothesis.
2) Write the null and alternative hypotheses for the claim that
p  0.70 .
3) Find the critical value(s) for a two-tailed z-test at   0.05 ,
n = 96
4) What test for the mean do we use if we do not know the
population standard deviation?
5) A cereal maker claims that the mean number of fat calories in
one serving of its cereal is less than 20. Is this right-tailed, lefttailed, or two-tailed?
6) A company’s shipping department believes its employees
monthly number of shipping errors is less than 30. The company
wants to give a reward to its employees if the have under 30
errors. After running the hypothesis test, the company decides to
reward its employees. However, the employees are making
between 40-45 errors per month. What type of error occurred?
7) Test the claim:   0 ;   0.05 ; x  0.69 ; s  2.62 ; n  60 .
What can you conclude?
8) Write the hypotheses for a bottle manufacturer’s claim that the
standard deviation of liquid soap dispensed is no more than
0.0025 liters.
9) Use the following information to determine whether H or H a
0
is the claim: A state school administrator says that the standard
deviation of SAT math test scores is below 105.
10) What symbol does  represent?
11) Test the claim:   230 ;   0.01; x  216.5 ; s  17.3 ; n  48
What can you conclude?
12) A citrus grower’s association believes that the mean
consumption of fresh citrus fruits is more than 94 pounds per year.
A random sample of 103 people has a mean consumption of 97.5
pounds per year and a standard deviation of 30 pounds. At
  0.02 , what conclusion can you make about the association’s
claim that the mean consumption of fresh citrus fruits is more than
94 pounds per year?
H0 :   5
13) Given: H :   5 (claim ) ;  = 0.05; p-value = 0.02. What
a
conclusion would you draw?
14) Find the critical value(s) for the test that is right-tailed,
 = 0.01
n = 8,
15) Given the normally distributed data, what would the t0 be?
Claim  > 12,700;  = 0.05, Statistics x  12,804 , s = 248,
n = 21
16) Test the claim that: Claim  > 12,700;  = 0.05, Statistics
x  12,804 , s = 248, n = 21
17) Test the claim that: Claim  > 12,700;  = 0.01, Statistics
x  12,804 , s = 248, n = 21
18) A large university says the mean number of classroom hours
per week for full-time faculty is more than 9. A random
sample of the number of classroom hours for full-time faculty
for one week is listed. At  = 0.01, test the association’s
claim.
10.7 9.8 11.6 9.7 7.6 11.3 14.1 8.1 11.5 8.5 6.9
19) Decide whether the normal distribution can be used to
approximate the binomial distribution.
Claim p > 0.70;  = 0.01, Statistics pˆ  0.50 , n = 68
20) Test the claim about the population proportion p for the:
Claim p > 0.125;  = 0.01, Statistics pˆ  0.238 , n = 45
21) An insurance agent says that the mean cost of insuring a 2010
Ford F-150 Super Cab is at least $875. A random sample of
nine similar insurance quotes has mean cost of $825 and a
standard deviation of $62. Is there enough evidence to reject
the agent’s claim at  = 0.01? Assume the population is
normally distributed.
22) An insurance agent says that the mean cost of insuring a 2010
Ford F-150 Super Cab is at least $875. A random sample of
nine similar insurance quotes has mean cost of $825 and a
standard deviation of $62. Is there enough evidence to reject
the agent’s claim at  = 0.05? Assume the population is
normally distributed.
23) A coin is tossed 1000 times and 530 heads appear. At
= 0.01, test the claim that this is not a biased coin.

24) A coin is tossed 1000 times and 530 heads appear. At
= 0.10, test the claim that this is not a biased coin.

25) If you increase the sample size you will ____________ the
probability of a type I and type II error.