In 1920, the record for a certain race was 45.4 seconds. In 1980 it was 44.2 seconds. Let R(t) = the record in the race and t=the number of years since 1920.

R(t) =?

What is the predicted record for 2003?

2006?

And in what year will the predicted record be 43.64 seconds?

Question

In 1920, the record for a certain race was 45.4 seconds.  In 1980 it was 44.2 seconds.  Let R(t) = the record in the race and t=the number of years since 1920.

R(t) =?

What is the predicted record for 2003?

2006?

And in what year will the predicted record be 43.64 seconds?

a_clan · Answer

R(t)= 45.4 - 0.02t

 for 2003, t= (2003-1920)=83 
So, R(83) = 45.4 - 0.02*83 = 43.74

 Similarly for 2006, t= 86

last part of the question, 
43.64 = 45.4 - 0.02t
Add this t to 1920