To calculate the average weights of the two rabbit breeds, we first sum the weights of each breed and then divide by the number of rabbits in each group. For Breed A, the average weight is (10 + 8 + 7 + 10 + 9 + 9 + 10 + 9) / 8 = 9.0 pounds. For Breed B, the average weight is (10 + 12 + 14 + 13 + 10 + 15 + 11 + 12) / 8 = 12.5 pounds.
Factors contributing to the different weights within breeds could include genetics, diet, age, health, and environmental conditions where the rabbits are raised. To track and find the growth rate of the two rabbit breeds during an investigation, I would take regular weight measurements over a defined period, such as weekly or bi-weekly, along with monitoring their diet and health status, and maintaining records in a spreadsheet to analyze trends in growth and compare between the two breeds.