Need to use a the table given to find the rate of change in fruit flies per day over the given intervals. not sure how to use the table with the other info given?

Given a table, with an input (x) and output (y) , you could actually use the slope formula to get the rate of change because slope is the same thing as rate of change. If you recall, the slope formula is (y2-y1)÷(x2-x1)
Just pick two points from the chart and plug them in and that is your rate of change