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Name:_________________________
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Test the indicated claim about the means of two populations. Assume that the two samples are independent and that they
have been randomly selected.
1) A researcher wishes to determine whether people with high blood pressure can reduce their blood pressure by
following a particular diet. Use the sample data below to test the claim that the treatment population mean µ1 is
smaller than the control population mean µ2 . Test the claim using a significance level of 0.01.
Treatment Group
n 1 = 85
Control Group
n 2 = 75
x1 = 189.1
x2 = 203.7
s1 = 38.7
s2 = 39.2
Use the traditional method of hypothesis testing to test the given claim about the means of two populations. Assume that two
dependent samples have been randomly selected from normally distributed populations.
2) A test of abstract reasoning is given to a random sample of students before and after they completed a formal
logic course. The results are given below. At the 0.05 significance level, test the claim that the mean score is not
affected by the course.
Before 74 83 75 88 84 63 93 84 91 77
After
73 77 70 77 74 67 95 83 84 75
Test the indicated claim about the variances or standard deviations of two populations. Assume that the populations are
normally distributed. Assume that the two samples are independent and that they have been randomly selected.
3) Test the claim that population A has a larger standard deviation than population B. Use a significance level of
0.01.
Sample A
Sample B
n = 61
n = 41
x1 = 190.1
s = 33.9
1
x2 = 242.5
s = 26.7
Use the traditional method of hypothesis testing to test the given claim about the means of two populations. Assume that two
dependent samples have been randomly selected from normally distributed populations.
4) Ten different families are tested for the number of gallons of water a day they use before and after viewing a
conservation video. At the 0.05 significance level, test the claim that the mean is the same before and after the
viewing.
Before 33 33 38 33 35 35 40 40 40 31
After
34 28 25 28 35 33 31 28 35 33
Test the indicated claim about the variances or standard deviations of two populations. Assume that the populations are
normally distributed. Assume that the two samples are independent and that they have been randomly selected.
5) Test the claim that populations A and B have different means. Use a significance level of 0.10.
Sample A
Sample B
n = 28
n = 21
x1 = 19.2
x2 = 23.7
s = 5.7
2
s = 6.05