The prediction equation relating x = years of education and y = annual income (in dollars) is ˆy = −20,000+

4000x, and the correlation equals 0.50.

The standard deviations were 2.0 for x and 16,000 for y.

(a) Show how to find the correlation from the slope.

(b) Results were translated to units of euros, at a time when the exchange rate was $1.25 per euro. Find the prediction equation and the correlation.