SOLUTION: In 1920 a record for a race was 45.3 seconds. In 1940 it was 44.7 seconds. R(t)= the Records of the race and let t = the number of years since 1920. 1.Find a linear function

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: In 1920 a record for a race was 45.3 seconds. In 1940 it was 44.7 seconds. R(t)= the Records of the race and let t = the number of years since 1920. 1.Find a linear function       Log On


   



Question 377863: In 1920 a record for a race was 45.3 seconds. In 1940 it was 44.7 seconds.
R(t)= the Records of the race and let t = the number of years since 1920.
1.Find a linear function that fits the Data
2. Use the function to predict the race 2003, and 2006
3. Find the year when the record will be 42.5 seconds.

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
In 1920 a record for a race was 45.3 seconds.
In 1940 it was 44.7 seconds.
decrease per year = (45.3-44.7) /20
=0.6/20
=0.03 per year.
R(t) = 45.3-0.03t
......
In 2003
-------------
R(83)= 45.5-0.03*83
R(83)=45.5 -2.49
R(83)=42.81
In 2003 the record will be 42.81 seconds.
plug t=86 for 2006
..
3.) 42.5 = 45.5 -0.03t
0.03t=45.5-42.5
0.03 t = 3
t = 3/0.03
t=100
Add 100 years to 1920= 2020
In 2020 the recoed will be 42.5 seconds
m.ananth@hotmail.ca