Although natural fibers like manila, sisal, and cotton were once the predominant rope materials, industrial synthetic fibers dominate the marketplace today, with most ropes made of nylon, polyester, or polypropylene.

One of the principal traits of rope material is its breaking strength. Assume that a research project generated the data given in the file titled Knots. The data listed were gathered on 10 different days from 12

-diameter ropes.

a. Test to determine if inserting the day on which the testing was done was necessary. Use a significance level of 0.05.

b. Based on the data, can it be concluded that there is a difference in the average breaking strengths of nylon, polyester, and polypropylene?

c. If you concluded that there was a difference in the average breaking strength of the rope material, use Fisher’s LSD approach to determine which material has the highest breaking strength.