Answer:

We assume that y represent the number of pages predicted and x the number of chapters.
And we want to find the predicted value for a book of x =8 chapters. S replacing we got:

And we can conclude that approximately we would have between 133 and 134 pages for a book of 8 chapters
Explanation:
For this case we have the following model given:

We assume that y represent the number of pages predicted and x the number of chapters.
And we want to find the predicted value for a book of x =8 chapters. S replacing we got:

And we can conclude that approximately we would have between 133 and 134 pages for a book of 8 chapters