Two hundred census tracts in a city are selected at random.It is found that 100 of these tracts are serviced by a community center; the others are not. You compare the delinquency rates for these two types of tracts and obtain the following sample results: Without Center With Center Sample Size 100 100 Mean Delinquency Rate 35 25 Standard Deviation 8 6 Test the null hypothesis that there is no difference in the delinquency rates for the two types of tracts. Use a significance level of .05. From the data in problem #1, construct a 95% confidence interval around the difference in population means.Interpret your answer. For the following random samples of scores, test the null hypothesis that the mean of population A is less than or equal to the mean of population B.Use a significance level of .05. (Note that you will first need to calculate the sample means and sample standard deviations.) Sample A Sample B 15 10 18 11 12 12 17 10 19 10 In a recent poll, 70% of the 600 female respondents said they would vote for a woman president, while 50% of the 500 male respondents said they would vote for a woman president. Construct a 95% confidence interval around the difference in population proportions. Test the null hypothesis that the percentage of females who would vote for a woman president is less than or equal to the percentage of males who would so vote. Use a significance level of .05.
- Two hundred census tracts in a city are selected at random.It is found that 100 of these tracts are serviced by a community center; the others are not. You compare the delinquency rates for these two types of tracts and obtain the following sample results:
Without Center With Center
Mean Delinquency Rate 35 25
Standard Deviation 8 6
Test the null hypothesis that there is no difference in the delinquency rates for the two types of tracts. Use a significance level of .05.
- From the data in problem #1, construct a 95% confidence interval around the difference in population means.Interpret your answer.
- For the following random samples of scores, test the null hypothesis that the mean of population A is less than or equal to the mean of population B.Use a significance level of .05. (Note that you will first need to calculate the sample means and sample standard deviations.)
Sample A Sample B
15 10
18 11
12 12
17 10
19 10
- In a recent poll, 70% of the 600 female respondents said they would vote for a woman president, while 50% of the 500 male respondents said they would vote for a woman president.
- Construct a 95% confidence interval around the difference in population proportions.
- Test the null hypothesis that the percentage of females who would vote for a woman president is less than or equal to the percentage of males who would so vote. Use a significance level of .05.
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