The graph below shows the rate of natural gas usage (in therms per day) in one household for a 30 - day period. Estimate the total number of therms used during this period. Use left endpoints and rectangles with widths of 3 days.

View graph at:

postimg.o rg/image/61nw3co3r/

I came up with ans 165.

1 answer

it's ok. I got it now.