7. The tables below show the number of jumping jacks completed after a given period of time in minutes. Kimberly Time (min) # Jumping Jacks 3 28 8 58 12 82 16 106 Katrina Time (min) # Jumping Jacks 2 16 5 40 12 96 20 160

Answer 1

The rate at which Kimberly completes jumping jacks can be calculated by dividing the change in the number of jumping jacks by the change in time.

For the time period from 3 minutes to 8 minutes:
Rate = (58 - 28) / (8 - 3) = 30 / 5 = 6 jumping jacks per minute

For the time period from 8 minutes to 12 minutes:
Rate = (82 - 58) / (12 - 8) = 24 / 4 = 6 jumping jacks per minute

For the time period from 12 minutes to 16 minutes:
Rate = (106 - 82) / (16 - 12) = 24 / 4 = 6 jumping jacks per minute

Therefore, Kimberly completes jumping jacks at a constant rate of 6 jumping jacks per minute.

Similarly, we can calculate the rate at which Katrina completes jumping jacks for each time period.

For the time period from 2 minutes to 5 minutes:
Rate = (40 - 16) / (5 - 2) = 24 / 3 = 8 jumping jacks per minute

For the time period from 5 minutes to 12 minutes:
Rate = (96 - 40) / (12 - 5) = 56 / 7 = 8 jumping jacks per minute

For the time period from 12 minutes to 20 minutes:
Rate = (160 - 96) / (20 - 12) = 64 / 8 = 8 jumping jacks per minute

Therefore, Katrina completes jumping jacks at a constant rate of 8 jumping jacks per minute.