Understanding Variation
a. Find an expression for the unexplained variation in terms of the sample size n and the standard error of estimate se.
b. Find an expression for the explained variation in terms of the coefficient of determination r 2 and the unexplained variation.
c. Suppose we have a collection of paired data for which r 2 5 0.900 and the regres- sion equation is yˆ 5 3 2 2x. Find the linear correlation coefficient.