=+18. Suppose data is collected on two quantitative variables, x and y. Let r be the corresponding sample correlation coefficient for (x, y). The x and y values are then transformed as follows: x= 5 a 1 bx, y= 5 c 1 dy where

a, b,

c, and d are constants. Let r

=

be the corresponding sample correlation coefficient for (x=

, y=

).

a. Show that x= 5 a 1 bx and y= 5 c 1 dy.

b. Show that sx= 5 bsx and sy= 5 dsy.

c. Show that r 5 r

=

.