A linear function can be used to estimate the decrease in snowfall measured since 1920 the decrease in the annual snowfall has been an average of 0.24 in per year let X represent the number of years since 1920 when the measurements began and let y represent the annual snowfall the initial measurement in 1920 was 48.6 in using the average change and initial measurement which is the best estimate of the annual snowfall and the 78th year after records were kept round to the nearest hundredth of a 15.84 in B 27.72 in C 29.88 in D 67.32 in