1. Find Regression line equations from x = 39.5, y = 47.5, 6x = 10.8, 6y = 15, r = 0.42

Solution:
`byx = r * (sigma y)/(sigma x)`

`byx = 0.42 * 15/10.8`

`byx = 0.58`


Regression Line y on x
`y - bar y = byx (x - bar x)`

`y - 47.5 = 0.58 (x - 39.5)`

`y - 47.5 = 0.58 x - 23.04`

`y = 0.58 x - 23.04 + 47.5`

`y = 0.58 x + 24.46`


`bxy = r * (sigma x)/(sigma y)`

`bxy = 0.42 * 10.8/15`

`bxy = 0.3`


Regression Line x on y
`x - bar x = bxy (y - bar y)`

`x - 39.5 = 0.3 (y - 47.5)`

`x - 39.5 = 0.3 y - 14.36`

`x = 0.3 y - 14.36 + 39.5`

`x = 0.3 y + 25.14`