1. Consider the Data Set BONEDEN.DAT at www.cengagebrain.com. Calculate the difference in bone density of the lumbar spine (g/cm²) between the heavier-smoking twin and the lighter-smoking twin (bone density for the heavier smoking twin minus bone density for the lighter-smoking twin) for each of the 41 twin pairs. Suppose smoking has no relationship to bone density. What would be the expected number of twin pairs with negative difference scores? What is the actual number of twin pairs with negative difference scores? Do you feel smoking is related to bone density of the lumbar spine, given the observed results? Why or why not? A yes/no answer is not acceptable.

2. Answer Problem 4.75 for bone density of the femoral shaft?