Question: To analyze their relative effects on premenopausal bone mass, investigators studied the impact of several variables on vertebral bone density (VBD). Subjects were 63 premenopausal patients from a busy New York OB-GYN practice between the ages of 19 and 40. Among the findings were a correlation between an estrogen score and VBD (r=0.44, p < 0.001) and between age at menarche and VBD (r= -0.30, p = 0.03). For this study, answer the following questions:

a. What is the independent variable(s)?

b. What is the dependent variable?

c. What is the sampled population?

d. What is the target population?

e. What are the appropriate null and alternative hypotheses?

f. Do you think the null hypothesis was rejected? Explain why or why not.

g. What was the more relevant objective of the study, prediction or establishing and measuring a relationship (association)?

h. Are the variables directly or inversely related?