Question Set 1: Proportion Smoking Students
A professor gave a survey to a large random sample of college students. Of the 362 students in the sample, 43 said they smoked.
A. Use Minitab Express to construct a 95% confidence interval to estimate the proportion of all students who smoke. Check assumptions and, if assumptions were met, use the normal approximation method. Remember to include all relevant Minitab Express output and to clearly identify your answer. Other than checking assumptions, do not do any hand calculations. [15 points]
B. What sample size would be needed to construct a 95% confidence interval to estimate the proportion of all students who smoke with a margin of error of ±1%? Use the observed sample proportion as an estimate for the population proportion. You will need to do hand calculations. Show all of your work. [10 points]
C. A Student Affairs professional wants to know if there is evidence that less than 15% of all college students smoke. Use the five-step hypothesis testing procedure outlined below to address this research question. The only hand calculation you will need to do will be in step 1 to check assumptions. Use Minitab Express for steps 2 and 3. Remember to include all relevant Minitab Express output and to clearly identify your test statistic and p value. [25 points]
Step 1: Check assumptions and write hypotheses
Step 2: Calculate the test statistic
Step 3: Determine the p value
Step 4: Decide to reject or fail to reject the null
Step 5: State a "real world" conclusion