The answer is going to be <span>181.121506177483. hope that helped</span>
6 songs
The way to find this answer is to divide 18 by 3, which is six, which means that after every six songs a commercial is played.
Hope this was helpful and that I explained it correctly.
Answer:

Step-by-step explanation:
Given that

We have slope of linear regression line is

So regression line would be of the form
(since it passes through xbar, y bar)

is the equation of regression line.