Monthly on-line quiz

Looks like a decaying exponential curve. The equation is of the form y = A e^(-kx) where A and k are constants. I will spare you the answer.

If you want an easier way to do this than running an exponential fit, look at the ratio between the 9 and 10 value (44/31 = 1.42). Notice that it is the same as the ratio between the 3 and 4 value (353/250 = 1.41) . Every time the number goes down by one, the value goes up by around 41.4% give or take due to rounding. So you would guess that if 2, then 353 x 1.414 = ~500.