Math 116
posted by Kim .
In 1920, the record for a certain race was 45.7 sec. In 1950, it was 45.1 sec. Let Ra9ta0=the record in the race and the number of years since 1920. A. Find a linear function for the data B. Use the function in (a) to predict the record in 2003 and in 2006. C. Find the year when record will be 43.92 seconds.

The record supposedly drops 0.6 seconds every 30 years, or 0.02 seconds per year.
R(t) = 45.7  0.02 t
When R = 43.92,
0.02 t = 1.78
t = 89 years after 1920
That makes it 2009.
Those look like world record times for the men's 400 meter hurdles. Actually the record is lower now. Records are really not broken at a constant rate per eat.