A researcher examines the correlations between mental health and three other measuresincome, age, and number of major physical illnesses. The correlations are .24, .18, and -.47, respectively.

1. Which variable will produce the best prediction of mental health?
2. Which variable will produce the least accurate prediction of mental health?

Wayne has just taken a statistics exam (Test A). He is disappointed because he did rather poorlyhe got the lowest score in the class. His instructor gives him the option of taking another test over the same material (Test B). The instructor also knows that the correlation between Test A and Test B is .30 (which is rather low).

Would you encourage Wayne to take Test B? What statistical reasons can you provide for your recommendation?