The Seven Countries Study, conducted by Ancel Keys, was a long-term study of the relationship of cholesterol to coronary heart disease (CHD) mortality in men. The relationship was approximated by the line shown in the accompanying figure. The line passes through the points (200, 25) and (250, 49), which means there were 25 CHD deaths per 1000 among men with 200 mg/dl (milligrams per deciliter) of cholesterol and 49 CHD deaths per 1000 among men with 250 mg/dl of cholesterol. Using x to represent the cholesterol and y to represent CHD deaths, write the equation that represents this relationship.

Median cholesterol (mg/dl)

150 200 250 10-year coronary deaths per 1000