and we're interested in the probability, we have one unknown. (X% chance of death, August 25th, 2012) (X%, 238th day of 2012) We can use  interpolation  to determine how likely it was to happen. x = x_a + (x_b-x_a)*(y-y_a)/(y_b-y_a) X% = 5 + (50-5) * (238-222)/(596-222) X% = 6.925% Thus, pretty