A public policy researcher wanted to investigate if there was a relationship between an individuals student loan debt (measured in $1,000s) at graduation and their credit score at age 35. Credit score is measured as a standardized scale between 300 points (poor credit) and 900 points (excellent credit).

A random simple random sample of 200 graduates, 35 years of age was selected to investigate this.

a) [2 marks] Identify the two variables in this study. What measurement scale is used for each variable.

b) [4 marks] Suppose the sample correlation coefficient was found to be -0.321. What conclusion can we make about all graduates in the population? Make sure you use the appropriate process (hypothesis testing) to make the conclusion.

c) [2 marks] Can we say, "student loan debt at graduation causes poor credit at age 35"? Briefly justify your answer.