in 1920 the record for a certain race was 45.9 seconds. In 1960 it was 44.7 sec. let R(t) = the record in the race and t=the number of years since 1920.
a. find a linear function that fits the data
b. use the function in (a) to predict the record in 2003 and in 2006
c. find the year when the record will be 43.26 sec.
round to nearest hundredth

Question

in 1920 the record for a certain race was 45.9 seconds.  In 1960 it was 44.7 sec. let R(t) = the record in the race and t=the number of years since 1920.
a.  find a linear function that fits the data
b.  use the function in (a) to predict the record   in 2003 and in 2006
c. find the year when the record will be 43.26 sec. 
round to nearest hundredth

anonymous · Answer

fairly simple

anonymous · Answer

take t=0 to represent yr 1920

therefore we have two points on the line ( 0, 45.9 ) and ( 40 , 44.7 )

anonymous · Answer

you know two points you can make a line

anonymous · Answer

gradient = (44.7 -45.9 ) / (40) = -0.03

and the y intercept ( when x=0 ) is 45.9

anonymous · Answer

so r(t) = -0.03t +45.9

anonymous · Answer

you can do the rest, its very easy stuff