In "Introduction to statistical learning wit R", there's a simple linear regression fit on a 'TV' feature where the target class is the 'Sales'.
Beta 0 is 7.03 and Beta 1 is 0.0475
Now we want to predict how much sales will increase when 1000 dollars is spent on TV advertising. I naturally thought that this would
1000 * 0.0475 + 7.03
which equals to 54.6
The book however says that it's 47.5 which i presume is because
1000 * 0.0475
I then ran my own linear regression model on the data, and asked it to predict on the 1000 dollars and it agreed with me that it's 54.6
which is it?