Construct a scatterplot of the data. Does the appearance of the scatterplot indicate that the pairing was effective?
(a) In an agronomic field experiment, blocks of land were subdivided into two plots of 346 square feet each. Each block provided two paired observations: one for each of the varieties of wheat. The plot yields (lb) of wheat are given in the table.

(b) In an experiment to compare two diets for fattening beef steers, nine pairs of animals were chosen from the herd; members of each pair were matched as closely as possible with respect to hereditary factors. The members of each pair were randomly allocated, one to each diet. The following table shows the weight gains (lb) of the animals ever a 140-day test period on diet 1(Y1,) and on diet 2 (Y2).

(c) Under certain conditions, electrical stimulation of a beef carcass will improve the tenderness of the meat. In one study of this effect, beef carcasses were split in half; one side (half) was subjected to a brief electrical current, and the other side was an untreated control. For each side, a steak was cut and tested in various ways for tenderness. In one test, the experimenter obtained a specimen of connective tissue (collagen) from the steak and determined the temperature at which the tissue would shrink; a tender piece of meat tends to yield a low collagen shrinkage temperature. The data are given in the following table

Variety Block 32.1 30.6 33.7 29.7 31.53 2 34.5 32.6 34.6 31.0 33.18 Difference -2.4 -2.0 -0.9 1.3 Mean 1.65 0.68 SD 1.76 1.72 Pair Diet 1 596 422 524 454 Diet 2 498 460 468 458 530 482 528 598 456 497.6 47.3 Difference 98 -38 56 552 478 564 556 520.4 70 -34 Mean SD 100 22.9 59,3 2 57.1 Collagen shrinkage temperature (C) Carcass Treated side Control side Difference 69.50 67.00 70.75 68.50 66.75 68.50 69.50 69.00 66.75 69.00 69.50 69.00 70.50 68.00 69.00 68.750 1217 70.00 69,00 69.50 69.25 67.75 66.50 68,75 70,00 66.75 68.50 69.00 69.75 70.25 0.50 -2.00 1.25 0.75 2.00 0.75 0.00 10 12 13 14 15 Mean SD 0.50 0.75 0.25 1.75 0.75 68.25 68,633 1.302 L118