15.49 Tennis Racquets The data shown in the accompanying table give measures of bending stiffness and twisting stiffness as determined by engineering tests on 12 tennis racquets.

a. Calculate the rank correlation coefficient r, between bending stiffness and twisting stiffness.

b. If a racquet has bending stiffness, is it also likely to have twisting stiffness? Use the rank correlation coefficient to determine whether there is a significant positive relationship between bending stiffness and twisting stiffness. Use = 0.05.

Transcribed Image Text:

Racquet Bending Stiffness Twisting Stiffness 12 419 227 407 231 3 363 200 4 360 211 5 257 1821 6 622 304 7 424 384 8 359 194 9 346 158 10 556 225 11 474 305 12 441 235