RES 342 FINAL EXAM

1) The area of rejection, on a bell shaped curve, defines the location of
all those values that are
A. so small or so large that the probability of their occurrence under a false
null hypothesis is rather remote
B. so small or so large that the probability of their occurrence under a true
null hypothesis is to be expected
C. so small or so large that the probability of their occurrence under a true
null hypothesis is rather slim
D. within the selected confidence interval for the test
2) If the decision is to reject the null hypothesis of no difference between
two population parameters, z distribution at the .01 significant level, what is
the correct statement of the alternate hypothesis and rejection region?
A. µ1 ? µ2 ; z > 1.96 and z < negative 1.96 B. µ1 > µ2; z < negative 2.33 C. µ1 > µ2; z > 2.33
D. µ1 ? µ2 ; z > 2.58 and z < negative 2.58 3) The statement that determines if the null hypothesis is rejected or not is called the A. test statistic B. alternate hypothesis C. critical value D. decision rule 4) The Roman Senate has become concerned about the loyalty of the army in Gaul commanded by Julius Caesar. They claim that, of the 80,000 men in the army, at least 28,000 are foreign barbarians. Caesar believes there are fewer barbarians, so the Senate should not worry. He polls one legion of 1,000 men and finds that 340 of them are barbarians. What is the test statistic for this hypothesis test? A. (0.34-0.35)/0.015 B. (0.35-0.34)/0.2275 C. (0.34-0.35)/0.063 D. (0.35-0.34)/100 5) A statistician was setting up a hypothesis test with a level of significance dictated by upper management. However, she was concerned that the test she wished to perform might have unacceptable large possibilities of Type II error, ß. Which of the following would solve this problem? A. Convince upper management to use a larger sample. B. Convince upper management to use a smaller p-value. C. Convince upper management to reduce the level of significance of the test. D. Convince upper management to use a larger p-value. 6) In classical hypothesis testing, the test statistic is to the critical value what the ________________. A. critical value is to alpha B. p-value is to alpha C. level of significance is to the test statistic D. test statistic is to the p-value 7) When testing for differences between two means, the Behrens-Fisher problem arises when the sample populations are A. are normal with unequal variances. B. normal with equal variances. C. are non-normal and have unequal variances. D. are non-normal and have equal variances. 8. If the paired differences are normal in a test of mean differences, then the distribution used for testing is the A. Chi-Square B. normal distribution C. F distribution D. Student t distribution 9) You are conducting a two-tailed test of means but your software package only calculates a one-tailed p-value equal to 0.13. The actual p-value for your test is A. 0.065 B. 0.13 C. need a table to calculate this value. D. 0.26 10) One hundred women were polled and 60 reported successfully communicating an automobile problem to an auto repairman. A sample of 150 men had 95 reporting the same success. The value of the test statistic for a test of the equality of proportions is A. 0.7293. B. -0.5319. C. 0.2702. D. -0.419. 11) A recent study by College Stat Company reported a nationwide survey of college students determined that students spend 2 hours studying for each hour in the classroom. Professor Baker at State College wants to determine whether the time students spend at her college is significantly different from the national average of 2 hours. A random sample of 20 statistics students resulted in an average of 1.75 hours with a standard deviation of 0.24 hours. A t-test was conducted at the 5% level of significance. The calculated value of t was -4.03. What was Professor Baker decision? A. Fail to reject the null hypothesis. B. Cannot make a decision at this time; more data is required. C. Reject the alternative hypothesis statement. D. Reject the null hypothesis, the test statistic exceeds the critical value. 12) Newton’s, a tire manufacturer, wanted to set a mileage guarantee on its new Road Warrior 60 tire. A sample test of 500 tires revealed that the tire’s mileage is normally distributed with a mean of 50,000 miles and a standard deviation of 1,750 miles. The warranty on the tires is presently set at 47,500 miles. The z-test statistic result was 1.43. The manufacturer wanted to determine if the tires were exceeding the guarantee. At the .05 significant level, it was concluded that the tires are exceeding the manufacturer’s guarantee. A. This was the correct decision. B. The decision needs to be delay until more data is collected. C. The evidence does not support this decision. D. A decision cannot be made. 13) Accounting procedures allow a business to evaluate their inventory at LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $ thousands) for five products both ways. Based on the following results, is LIFO more effective in keeping the value of his inventory lower? Product FIFO (F) LIFO (L) 1 225 221 2 119 100 3 100 113 4 212 200 5 248 245 The 5% level of significance was selected for the t value. This example is what type of test? A. Two sample test of means. B. One sample test of means. C. Test of proportions. D. Paired t-test. 14) When is it appropriate to use the paired difference t-test? A. Any two samples are compared B. Four samples are compared at once C. Two dependent samples are compared D. Two independent samples are compared 15) The owner of a bottling company is considering buying a new bottling machine. He has been testing two different machines that are being considered. After collecting 300 samples from each machine over several weeks, he was able to conduct a two sample z test.

He decided to utilize a 0.05
significant level for the test. The test was to address the claim that the mean
weight of the bottles filled by the Orno machine was greater than the mean
weight of the bottles filled by the Edne machine. The test statistics was 2.21.
What is the decision regarding the hypothesis?
A. Reject the null hypothesis; there is a significant difference.
B. This is a two tail test and the critical value for the test is 1.96.
C. There is not enough data available to answer the question.
D. Accept the null hypothesis; there is not a significant difference.
16) Two different accounting procedures that are utilized by businesses as a
way to evaluate their inventory are LIFO (Last In First Out) and FIFO (First In
First Out). ABC manufacturer evaluated its finished goods inventory (in $
thousands) for five products using both procedures. Based on the following
results, is LIFO more effective in keeping the value of his inventory lower?
Product FIFO (F) LIFO (L)
1 225 221
2 119 100
3 100 113
4 212 200
5 248 245
The 5% level of significance was selected for the t value. The calculated
test statistic was 1.93. What is the decision?
A. Reject the null hypothesis and conclude LIFO is more effective.
B. Fail to reject the null hypothesis and conclude LIFO is not more effective.
C. Fail to reject the null hypothesis and conclude LIFO is more effective.
D. Reject the alternate hypothesis and conclude LIFO is more effective.
17) You are conducting a two-tailed test of means, but your software package
only calculates a one-tailed p-value equal to 0.13. The actual p-value for your
test is
A. 0.065.
B. You need a table to calculate this value.
C. 0.13.
D. 0.26.
18. A consumer researcher is testing the difference between two proportions
at the 0.05 level of significance. The researcher was utilizing the z
distribution for the test. If the computed test statistic z value was 1.12,
what was the decision?
A. Do not reject the null hypothesis.
B. Reserve judgment.
C. Reject the null hypothesis.
D. Take a larger sample.
19) Watson’s TV claims that their televisions have the best performance
record on the market. They advertise that after 3 years only 10% of their sold
televisions have had any type of repairs. The president of the company wanted
to confirm that this statement was correct. To do this, a sample of 60 sets was
taken of sets that had been sold and were at least 3 years old. Twelve percent
of these television sets had been in for repair. The null hypothesis is that
there is no difference between the stated percent and the sample data. At the
.05 significant level, what can we conclude about the null hypothesis?
A. The data fails to reject the null hypothesis.
B. The difference is too close to be able to decide.
C. The null hypothesis is rejected and the difference is significant.
D. The sample is too small to be able to decide.
20) The accountant for Thomas’s Furniture Store is concerned regarding the
outstanding receivable owed the company. There has been a cash flow problem and
it is believed that the slow collection of accounts receivable is partially the
blame. The accountant believes that 40% of the present accounts are more than 4
months behind in making payments. To be able to make a decision regarding this
belief, a random sample of 100 accounts was taken. It was found that 37
accounts were more than 4 months late. Did the sample data confirm the
accountant’s belief? Use the .05 significant level for the statistical test.
A. The accountant belief is not conferred.
B. The accountant needed to take a larger sample.
C. There is not enough evidence to confer or deny the belief.
D. The accountant belief is conferred.