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Question 260292:  In 1920, the record for a certain race was 45.8 sec. In 1959, it was 44.9 sec. Let R(t)= the record in the race and t=the number of years since 1920
 
Find a linear function that fits the data
 
R(t)= 
What is the predictd record for 2003? sec.
 
What is the predicted record for 2006
 
In what year will the predicted record be 43.10 seconds
 
Round to the nearest hundredth 
 Answer by drk(1908)      (Show Source): 
You can  put this solution on YOUR website! We start with our coordinates in disguise: 
(1920, 45.8) and (1959,44.9), however, time is years "since" 1920, so we readjust to get 
(0, 45.8), (39, 44.9). 
step 1 - we can find the slope of these as 
  
  
  
step 2 - using this slope and a coordinate, we can find the linear equation as 
  
  
  
step p 3 - write the linear equation as 
  
-- 
find time for 2003? t = 83, so we get 
  
  
-- 
find time for 2006? t = 86, so we get 
  
  
-- 
In what year will t = 43.10? 
  
subtract 45.8 to get 
  
divide by -0.0230769 to get 
t = 117 
or 2037. 
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