Sometimes the main purpose of a regression analysis is to determine the nature of the relationship between two variables, and sometimes the main purpose is to use the equation in the future to predict a y value when the x value is known. Explain which purpose is likely to be the main reason for a regression analysis between
x = percent fat consumed in diet, y = blood pressure
x = SAT score, y = college grade point average
x = height at age 4, y = height at age 21
x = hours of sleep per night, y = score on IQ test*