The following relates the breaking strength of eight pieces of rope and the percentage of that rope that is nylon (rather than cotton). Breaking strength Percentage nylon (pounds) 0 160 10 240 20 325...

The following relates the breaking strength of eight pieces of rope and the percentage of that rope that is nylon (rather than cotton).

(a) Plot the data in a scatter diagram.

(b) Give the estimated regression line.

(c) Predict the breaking strength of a new piece of rope that is 50 percent nylon.

(d) Give an interval that, with 95 percent confidence, will contain the breaking strength of a piece of rope that is 50 percent nylon.