The complete question is;
Marquis wrote the linear regression equation y = 1.245x - 3.685 to predict the cost, y, of x songs purchased. Marquis spent $40 on songs. Which is the best estimate of the number of songs that Marquis purchased?
Answer:
The best estimate of the number of songs that Marquis purchased = 35 songs
Explanation:
First of all, let's make x the subject of the linear regression equation.
We are given that,
y = 1.245x - 3.685
So,
1.245x = (y + 3.685)
x = (y + 3,685) / (1,245)
We are told that Marquis spent $40 on songs.
Thus;
Substituting the value of $40 for y into the equation to get;
x = (40 +3,685)/(1,245)
x = 35.09
x ≈ 35
Thus, the best estimate of the number of songs that Marquis purchased is 35