Answer:
1221.2 factor increase
Explanation:
It is difficult interpreting the numbers. I'll assume:
2.25x10^2 and 2.75x10^5
----
225
275000
The difference(increase) is 274775, or 2.75 x 10^5 to 3 sig figs
There is a (2.75 x 10^5)/(2.25x10^2) or 1221.2 factor increase in bacteria between the two weeks.