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Test for Week 3 Provide an appropriate response....

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Test for Week 3 Provide an appropriate response. 1) Suppose that you wish to perform a hypothesis test for a population mean. Suppose that the population standard deviation is unknown and the sample size is small. If the distribution of the variable under consideration is symmetric multimodal, should you use a t-test, a Wilcoxon signed-rank test, or neither? 1) ______ A) Wilcoxon signed-rank test B) t-test C) Neither Preliminary data analyses indicate that you can reasonably consider the assumptions for using the Mann-Whitney test satisfied. 2) A researcher was interested in comparing the GPAs of students at two different colleges. Independent simple random samples of 8 students from college A and 9 students from college B yielded the following GPAs. <> At the 10% significance level, do the data provide sufficient evidence to conclude that the mean GPA of students at college A differs from the mean GPA of students at college B? a) What is the p-value for this test? b) What is your decision (Reject/Fail to reject)? 2) ______ Provide an appropriate response. 3) Suppose that you want to perform a hypothesis test to compare the means of two populations using independent simple random samples. Suppose that preliminary data analyses of the samples suggest that the two distributions of the variable under consideration are skewed to the right and that both distributions have the same shape. The sample sizes are small. Should you use the pooled t-test, the nonpooled t-test, the Mann-Whitney test, or none of these tests? 3) ______ A) Mann-Whitney test B) nonpooled t-test C) pooled t-test D) none of these tests Preliminary data analyses indicates that use of a paired Wilcoxon signed-rank test is reasonable. 4) The systolic blood pressure readings of ten subjects before and after following a particular diet for a month are shown in the following table. <> At the 1% level of significance, do the data provide sufficient evidence to conclude that the diet has an effect on systolic blood pressure? a) What is the p-value for this test? b) What is your decision (Reject/Fail to reject)? 4) ______ Provide an appropriate response. 5) A chi-square goodness-of-fit test is to be performed. The relative frequencies for the null hypothesis and the sample size are given. True or false, the assumptions for using a chi-square goodness-of-fit test are satisfied? Sample size: n = 80 Relative frequencies: 0.26 , 0.01, 0.4, 0.12, 0.21 5) ______ A) True B) False A Chi-Square Goodness-of-Fit test is applicable to the following. ? 6) A firm that manufactures engines for racing boats gathers data from all of its plants. The table below gives the distribution of the life span of the engines (in numbers of months) for the entire firm. Months Relative Frequency Under 60 0.017 70-79 0.201 80-89 0.353 90-99 0.331 100-109 0.098 A random sample of 448 engines from the firm's Ohio plant gives the following results. Months Number of engines Under 60 22 70-79 131 80-89 46 90-99 154 100-109 95 At the 5% significance level, do the data provide evidence that the distribution of the life spans of the engines manufactured at the Ohio plant is different from the firm's overall distribution? a) What is the p-value for this test? b) What is your decision (Reject/Fail to reject)? 6) ______ Provide an appropriate response. 7) Suppose that a chi-square goodness-of-fit test is to be performed. True or false, the more closely the observed frequencies match the expected frequencies, the larger the value of the test statistic 7) ______ A) True B) False Used the Kruskal-Wallis test is applicable to the following 8) Listed below are grade averages for randomly selected students with three different categories of high-school background. At the 0.05 significance level, do the data provide sufficient evidence to conclude that a difference exists in the three population means? <> a) What is the p-value for this test? b) What is your decision (Reject/Fail to reject)? 8) ______ Provide an appropriate response. 9) True or false? A Kruskal-Wallis test can be used to compare several population medians as well as several population means 9) ______ A) True B) False

 

Paper#13124 | Written in 18-Jul-2015

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