1. Give the equation of the least-squares regression line. Define any variables you use.
2. Use the model from part (a) to predict the area covered by detergent at 5.5 seconds.
3. Based on the residual plot, do you expect the prediction you made in part (b) to underestimate or
overestimate the area covered by detergent? Justify your answer.
4. Is the least-squares regression line an appropriate model for these data? Justify your answer.