Question

Dan's grandmother gave him $30 for his birthday. He decides to put $20 in a box for saving. Every week his parents give him $5 for his allowance. He decides to start adding $4 of his allowance to the box every week. What is the regression line for predicting the amount of money (ŷ) that will be in his box from x weeks of adding to the box?

Answer 1

`y=4\cdot{x}+20`

Explanation:

Let the regresssion line be linear because of a constant amount of money coming in. Let y be the total amount of money in the box and x the weeks of adding to the box:

`y=m\cdot{x}+c`

We know that he puts $20 in the box from his birthday and $4 every week for x weeks. Therefore the total amount of money will be:

`y=4\cdot{x}+20`