For this Assignment, complete two problems that involve calculating confidence intervals with one sample.
1.The first problem involves calculating and interpreting the 90%, 95%, and 99% confidence intervals for a one-sample t-test.
2.The second problem involves calculating and interpreting the 95% confidence interval for a proportion.
3.While you can use SPSS to determine proportions, you need to calculate the confidence interval by hand.
Answer the following problems:
Problem 4.
1:
Given the data set body-weight.sav, use SPSS to calculate the 90%, 95% and 99% confidence intervals for the mean of the variable weight. Interpret the three confidence intervals in terms of whether there is a significant difference between the mean of the sample and a hypothesized mean of 150.
Problem 4.2:
Every year the CDC conducts phone surveys to assess the health risks of people in the U.S. This survey is abbreviated BRFSS, which stands for Behavioral Risk Factor Surveillance System. Review the following data collected for 2009:
Total number of respondents
|
Number of respondents who smoke everyday
|
Number of respondents who smoke some days
|
Number of respondents who are former smokers
|
Number of respondents who have never smoked
|
426,000
|
426,000
|
21,581
|
110,060
|
143,619
|
1.Calculate the proportion of each group of respondents.
2.Calculate the confidence interval for the proportion of respondents who stated they are former smokers.