To find the residual, we need to use the regression line equation and substitute the given values for advertising dollars and profit:
Profit = 372.6 + 17.2(1020)
Profit = 372.6 + 17544
Profit = 17916.6
The predicted profit for advertising dollars spent equal to $1020 is $17916.6. To find the residual, we subtract the predicted value from the actual value:
Residual = Actual profit - Predicted profit
Residual = 17500 - 17916.6
Residual = -416.6
Therefore, the value of the residual for advertising dollars spent equal to $1020 and profit equal to 17500 is approximately -417.