Draw a scatter diagram of the x, y data pairs and compare this diagram with the diagram of part (a). Which graph appears to better fi t a straight line?

(c) Use a calculator with regression keys to fi nd the linear regression equation for the data pairs x, y . What is the correlation coeffi cient?

(d) The exponential growth model is y 5 abx. Estimate a and b and write the exponential growth equation. Hint: See Problem 22.