For each table, calculate the mean weight for each group, XA and Xb, and find the difference of the mean of group A and the mean of group B (XA - XB).

First Randomization

Xa = 12.5, Xb = 11.26, Xa-Xb = 1.24

Second Randomization

Xa = 11.36, Xb = 12.6, Xa-Xb = -1.24

Third Randomization

Xa = 11.98 Xb = 11.98, Xa-Xb = 0

Step-by-step explanation:

Mean is the average weight of the numbers. The formula for calculating mean is as shown:

Mean xbar = sum of numbers/Total number present.

For first randomization:

Mean of A Xa = 13.6+12.1+15.9+11.2+9.7/5

Xa = 62.5/5

Xa = 12.5

Xb = 8.2+8.2+11.5+13.8+14.6/5

Xb = 56.3/5

Xb = 11.26

Mean difference Xa - Xb = 12.5-11.26

Xa-Xb = 1.24

For second Randomization:

Xa = 8.2+13.8+15.9+9.2+9.7/5

Xa = 56.8/5

Xa = 11.36

Xb = 12.1+14.6+13.6+11.2+11.5/5

Xb = 63.0/5

Xb = 12.6

Mean Difference Xa-Xb = 11.36-12.6

Xa-Xb = -1.24

For third randomization:

Xa = 8.2+9.7+11.5+14.6+15.9/5

Xa = 59.9/5

Xa = 11.98

Xb = 12.1+13.8+13.6+11.2+9.2/5

Xb = 59.9/5

Xb = 11.98

Mean Difference Xa-Xb = 11.98-11.98

Xa-Xb = 0

ok thats very interesting

use distributive property on all like terms and change your signs if you have a double negative or if you have positive/negative