Answer: Look at explanation for answer...
Explanation:
This could be turned into a simple proportion if you want to do it that way :)
1.) First, use the proportion bacteria over time.
2.) It should set up to look like this: 2,600 X
---------- = ---------
7 15
3.) You then do your math (2,600 * 15) (39,000 / 7)
Answer: Your answer then comes out to be: (rounded) 5,571 bacteria