To make the sure the results did not happen by chance, the coach can ensure that the protein bars are the only difference between the two groups. For example, he can make sure that both groups are drinking the same amounts of water and getting in the same amount of practice; that way, he will be able to determine that one group is performing better due to the protein bars only. Also, the coach can repeat this experiment multiple times to make sure that the results weren't a random, one-time thing.
The greatest possible temperature is
and least possible temperature is 
<u>Solution:</u>
Given that according to weather forecaster the temperature will be about -5 degree celsius given or take 10 degree”
Need to determine greatest possible temperature and least possible temperature.
Give and take in given statement means a temperature can go up by 10 degrees and can go down by 10 degrees
So greatest possible temperature will be 
Least possible temperature will be 
Hence according to weather forecaster, greatest possible temperature =
and least possible temperature = 
The answer is the 3rd graph