# Exam 4 (Chapter 9) Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Find the number of successes x suggested by the given statement. 1) Among 620 adults selected randomly from among the residents of one town, 25% said that they favor stronger gun-control laws. A) 154 B) 153 C) 156 D) 155
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From the sample statistics, find the value of p used to test the hypothesis that the population proportions are equal. 2) n 1 = 100 n 2 = 100 2) x1 = 36 A) 0.365 x2 = 37 B) 0.256 C) 0.329 D) 0.402
Determine whether the samples are independent or consist of matched pairs. 3) The effectiveness of a new headache medicine is tested by measuring the amount of time before the headache is cured for patients who use the medicine and another group of patients who use a placebo drug. A) Independent samples B) Matched pairs Find the appropriate p-value to test the null hypothesis, H0 : p1 = p2, using a significance level of 0.05. 4) n 1 = 100 x1 = 38 A) .2130 n 2 = 100 x2 = 40 B) .7718 C) .1610 D) .0412
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Construct the indicated confidence interval for the difference between population proportions p1 - p2. Assume that the samples are independent and that they have been randomly selected. 5) x1 = 20, n1 = 43 and x2 = 28, n2 = 60; Construct a 90% confidence interval for the difference between population proportions p1 - p2 . A) 0.660 < p1 - p2 < 0.270 C) - 0.166 < p1 - p2 < 0.162 B) 0.270 < p1 - p2 < 0.660 D) 0.301 < p1 - p2 < 0.629 5)
Construct the indicated confidence interval for the difference between the two population means. Assume that the two samples are independent and that they have been randomly selected. 6) A researcher wishes to determine whether people with high blood pressure can reduce their blood 6) pressure by following a particular diet. Use the sample below data to construct a 99% confidence interval for u1 - u2 where u1 and u2 represent the mean for the treatment group and the control group respectively. Treatment Group n 1 = 85 x1 = 189.1 Control Group n 2 = 75 x2 = 203.7 B) - 29.0 < 1 - 2 < - 0.2 D) - 1.3 < 1 - 2 < 30.5
s1 = 38.7 s2 = 39.2 A) - 26.7 < 1 - 2 < -2.5 C) - 30.9 < 1 - 2 < 1.7
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The two data sets are dependent. Find d to the nearest tenth. 7) A 56 59 55 63 51 B 27 25 21 25 22 A) 19.7 B) 42.6 Find sd.
7) C) 41.0 D) 32.8
8) The differences between two sets of dependent data are 3 , 21, 3 , 27, 15. Round to the nearest tenth. A) 10.7 B) 21.4 C) 8.6 D) 13.9
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Assume that you want to test the claim that the paired sample data come from a population for which the mean difference is d = 0. Compute the value of the t test statistic. 9) x 11 6 12 6 11 y 88 87 6 A) t = 1.292 9) B) t = 2.890 C) t = 0.578 D) t = 0.415
Determine the decision criterion for rejecting the null hypothesis in the given hypothesis test; i.e., describe the values of the test statistic that would result in rejection of the null hypothesis. 10) A farmer has decided to use a new additive to grow his crops. He divided his farm into 10 plots 10) and kept records of the corn yield (in bushels) before and after using the additive. The results are shown below. Plot: 1 2 3 4 5 6 7 8 9 10 Before 9 9 8 7 6 8 5 9 10 11 After 10 9 9 8 7 10 6 10 10 12 You wish the test the following hypothesis at the 1 percent level of significance. H0: D = 0 against H1 : D > 0. What decision rule would you use? A) Reject H0 if test statistic is greater than 2.821. B) Reject H0 if test statistic is greater than - 2.821. C) Reject H0 if test statistic is greater than - 2.821 or less than 2.821. D) Reject H0 if test statistic is less than 2.821.
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Answer Key Testname: UNTITLED1
1) D 2) A 3) A 4) B 5) C 6) C 7) D 8) A 9) A 10) A
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