Download RES342Q1 - Mathfiles.com

MULTIPLE CHOICE – 2 points each
1.
Of the following ordinary words, which one is most closely associated with the meaning of a
hypothesis?
a. trial
b. decision
c. outcome
d. assumption
2.
Whenever a hypothesis is tested, the evidence that is used to determine validity comes from the
a. decision.
b. conjecture.
c. sample data.
d. theory.
3.
All of the following are possible hypotheses surrounding nominal data except:
a. The percentage of people favoring brand A is greater than the percentage favoring brand B.
b. The average income of electricians exceeds the average income of carpenters.
c. The number of households with term life insurance exceeds the number with auto insurance.
d. There are more mountains over 20,000 feet high in Peru than there are in India.
4.
Borrowing from descriptions also associated with probability, the null hypothesis and the
alternative hypothesis are in essence
a. mutually exclusive and exhaustive.
b. independent and mutually exclusive.
c. independent and exhaustive.
d. mutually exclusive and independent.
5. The following steps are performed when testing a hypothesis of the mean:
1. Calculate the test statistic.
2. Select the value of  and determine the rejection region.
3. Set up the null and alternative hypotheses.
The correct sequence for performing each of these steps is
a. 1, 2, 3.
b. 2, 1, 3.
c. 3, 2, 1.
d. 3, 1, 2.
6. All of the following are examples of quantitative data except:
a. qualifying speeds of Indy 500 racing cars.
b. distances between cities in the United States.
c. percentage of women enrolled in a community college night course.
d. point spreads between competing college football teams.
7. The test statistic that is used to test hypotheses about the mean when a small sample is involved
follows a _________ distribution.
a. t
b. z
c. chi-square
d. binomial
8. When a two-tail test of the population mean is conducted, the value of the cutoff statistic is
obtained from the table by using the value of
a. /2
b. 
c. 2
d. 4
9. Given a two-tail test for the population mean, the null hypothesis contains a(n) __________ sign,
and the alternative hypothesis contains a(n) ___________ sign.
a. , =
b. =, 
c. , =
d. =, 
10. The final step to be performed when testing a hypothesis of the population mean is to
a. calculate the test statistic.
b. determine the size of the rejection region.
c. translate the decision in terms of the problem statement.
d. check to see if the test statistic falls into the rejection region.
11. A food processor is concerned that the 16 ounce can of sliced pineapple is being overfilled.
The quality control department took a random sample of 50 cans and found that the arithmetic
mean weight was 16.05 ounces, with a sample standard deviation of .03 ounce. At the 5%
significance, can the hypothesis that the mean weight is equal to 16 ounces be rejected? Explain.
Large-sample test of hypothesis about a population mean
TWO -TAILED TEST
H0:  =  0 = 16 oz
Ha:    0 = 16 oz
Test statistic:
16.05  16
=
0.03 / 50
 11.785
Rejection region: z > z/2
Z0.025 = 1.96
or z < - z/2 , where alpha = 0.05
where z is the z-value such that P(z > z) = ; and z/2 is the z-value such that P(z
> z/2) = /2. [Note: 0 is our symbol for the particular numerical value specified for
 in the null hypothesis.]
Assumption: The sample size must be sufficiently large (say, n  30) so that the
sampling distribution of
is approximately normal and that s provides a good
approximately to .
Conclusion: Since the calculated value of the test statistic is much greater than the
critical value of 1.96, we reject the null hypothesis. There is sufficient evidence to
conclude at 5% level of significance that the mean weight is different from 16
ounces.