Question : The owners of an industrial plant want to determine which of two types of fuel : 2150559
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
27) The owners of an industrial plant want to determine which of two types of fuel (gas or electricity) will produce more useful energy at a lower cost. The cost is measured by plant investment per delivered quad ($ invested /quadrillion BTUs). The smaller this number, the less the industrial plant pays for delivered energy. Random samples of 11 similar plants using electricity and 16 similar plants using gas were taken, and the plant investment/quad was calculated for each. In an analysis of the difference of means of the two samples, the owners were able to reject H0 in the test H0: (μE - μG) = 0 vs. Ha: (μE - μG) > 0. What is our best interpretation of the result?
A) The mean investment/quad for electricity is different from the mean investment/quad for gas.
B) The mean investment/quad for electricity is not different from the mean investment/quad for gas.
C) The mean investment/quad for electricity is less than the mean investment/quad for gas.
D) The mean investment/quad for electricity is greater than the mean investment/quad for gas.
Use the Wilcoxon rank sum test to determine whether the data provide sufficient evidence to indicate a shift in the locations of the probability distributions of the sampled populations. Use α = .05.
88) Verbal SAT scores for students randomly selected from two different schools are listed below. Use the Wilcoxon rank sum procedure to test the claim that there is no difference in the scores from each school. Use α = .05.
89) A researcher wants to know if the time spent in prison for a particular type of crime is the same for men and women. A random sample of men and women were each asked to give the length of sentence received. The data, in years, are listed below. Use the Wilcoxon rank sum procedure to test the claim that there is no difference in the sentence received by each gender. Use α = .05.
100) Nine students took the SAT test. Their scores are listed below. Later, they took a test preparation course and retook the SAT. Their new scores are listed below. Use the Wilcoxon signed rank test to test the claim that the test preparation had no effect on their scores. Use α = .05.
101) A weight-lifting coach claims that a weight-lifter can increase strength by taking vitamin E. To test the theory, the coach randomly selects 9 athletes and gives them a strength test using a bench press. The results are listed below. Thirty days later, after regular training supplemented by vitamin E, they are tested again. The new results are listed below. Use the Wilcoxon signed rank test to find the critical value to test the claim that the vitamin E supplement is effective in increasing the athletes' strength. Use α = .05.
102) A pharmaceutical company wishes to test a new drug with the expectation of lowering cholesterol levels. Ten subjects are randomly selected and their cholesterol levels are recorded. The results are listed below. The subjects were placed on the drug for a period of 6 months, after which their cholesterol levels were tested again. The results are listed below. (All units are milligrams per deciliter.) Use the Wilcoxon signed rank test to test the company's claim that the drug lowers cholesterol levels. Use α = .05.
103) A physician claims that a person's diastolic blood pressure can be lowered, if, instead of taking a drug, the person listens to a relaxation tape each evening. Ten subjects are randomly selected. Their blood pressures, measured in millimeters of mercury, are listed below. The 10 patients are given the tapes and told to listen to them each evening for one month. At the end of the month, their blood pressures are taken again. The data are listed below. Use the Wilcoxon signed rank test to test the physician's claim. Use α = .05.
104) A local school district is concerned about the number of school days missed by its teachers due to illness. A random sample of 10 teachers is selected. The numbers of days absent in one year is listed below. An incentive program is offered in an attempt to decrease the number of days absent.The number of days absent in one year after the incentive program is listed below. Use the Wilcoxon signed rank test to test the claim that the incentive program cuts down on the number of days missed by teachers. Use α = .05.
105) In a study of the effectiveness of physical exercise on weight loss, 20 people were randomly selected to participate in a program for 30 days. Use the Wilcoxon signed rank test to test the claim that exercise has no bearing on weight loss. Use α = .02.
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
106) Use the appropriate table to find the following F value:
F0.10, v1 = 2, v2 = 15
A) 2.52
B) 3.68
C) 2.70
D) 9.42
107) Find the following:
P(F ≤ 4.10), for v1 = 5, v2 = 20
A) 0.01
B) 0.99
C) 0.005
D) 0.995
108) Find the following:
P(F > 4.24), for v1 = 3, v2 = 14
A) 0.97
B) 0.01
C) 0.98
D) 0.025
