I can't figure out to set this up into an equation. If I could do that I could figure out the answer. I am desperate, please help me.

Cecilia is conducting a cell biology experiment and measures the number of bacteria in a culture at 2 hour intervals. Find the average hourly rate of change in the number of bacteria from 2 hours to 6 hours.

Time in hours 0 2 4 6

Number of Bacteria 100 200 400 800

Can someone please help me?

m_lynn6