Question: Describe and give examples of research questions for which external validity is a primary concern. Describe and give examples of research questions in which internal validity is a primary concern.
Question: A recent study indicated that women took an average of 8.6 weeks of unpaid leave from their jobs after the birth of a child. Assume that this distribution follows the normal probability distribution with a standard deviation of 2.0 weeks. We select a sample of 35 women who recently returned to work after the birth of a child. What is the likelihood that the mean of this sample is at least 8.8 weeks?
Question: The manager of the Tee Shirt Emporium reports that the mean number of shirts sold per week is 1,210 with a standard deviation of 325. The distribution of sales follows the normal distribution. What is the likelihood of selecting a sample of 25 weeks and finding the sample mean to be 1,100 or less?
Question: A researcher sampled 100 women from a medical record database and identified their smoking status and parity. Use the 5 steps of hypothesis testing to determine whether pregnancy and smoking status are independent.
Question: A medical student surveys adults to determine if gender and seat belt use are independent. Use the 5 steps of hypothesis testing to determine whether gender and seat belt use are independent.
Question: A researcher collected daily sodium intake and systolic blood pressure readings on 12 patients. Obtain the regression equation from SPSS and include the table you used for the data. Use the 5 step hypothesis testing approach to determine if the regression equation is significant at alpha = 0.05. What would be a likely blood pressure for a person with a sodium intake of 6.3: 7.6?