# algebra

posted by .

ok i don't get this one

in 1920 the record for a certain race was 45.9 sec in 1980 it was 44.1 sec let r (T) = the record in the race and t= the number of years since 1920

(a) find a linear fuction that fits the data
(b) use the funcation in (a) to perdict the record for 2003 and 2006
(c) find t he year when the record will be 43.20 sec..

• algebra -

r = m (t) + b
when year = 1920, t = 0
where t = year - 1920
45.9 = m (0) + b
so b = 45.9
44.1 = m (1980-1920) + 45.9
44.1 = 60 m + 45.9
60 m = -1.8
m = -.03
so
r =-.03 t + 45.9
when year = 2003
t = 2003 - 1920 = 83
r = -.03 (83) + 45.9
r = 43.41
that should get you started

• algebra -

so what yr will it be 43.20

• algebra -

so r(t)=?

• algebra -

as I said
r =-.03 t + 45.9

then
43.2 = -.03 t + 45.9
.03 t = 2.7
t = 90
1920 + 90 = 2010

## Similar Questions

1. ### algebra

In 1920 the record for a certain race was 45.4 sec. in 1950, it was 41.5 sec. let R(t) = the record in the race and t the number of years since 1920. R(t)=?
2. ### math (am i correct)

in 1920 the record for a certain race was 46.9 sec. In 1990 it was 45.5 sec. let R(t) = the record in the race and t = the number of years since 1920 1.)find a linear function that fits this data?
3. ### math

in 1920 the record for a certain race was 46.9 sec. In 1990 it was 45.5 sec. let R(t) = the record in the race and t = the number of years since 1920 what is the predicted record for 2006?
4. ### Algebra 1

in 1920, the record for a certain race was 45.8 sec. In 1980, it was 44.6 sec. Let R(t)=the record in the race and t=the number of years since 1920. find the linear function that fits the data use the function (a) to predict the record …
5. ### Math

In 1920, the record for a certain race was 46.6 sec. In 1980, it was 45.4 sec. Let R(t)= the record in the race and t = the number of years snce 1920. a) Find a linear function that fits the data R(t) = b) Use the function in (a) to …
6. ### Math

In 1920, the record for a certain race was 46.6 sec. In 1980, it was 45.4 sec. Let R(t)= the record in the race and t = the number of years snce 1920. a) Find a linear function that fits the data R(t) = b) Use the function in (a) to …
7. ### math

in 1920 the record for a certain race was 46.4 sec. In 1960 it was 45.6 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 …
8. ### Math

how do I solve this problem. In 1920 the record for a certain race was 445.7 sec. In 1970, it was 44.2 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 R(t) …
9. ### Algebra 1

In 1920 the record for a certain race was 45.1 sec. In 1960, it was 44.3 sec. Let R(t)= the record in the race t= the number of years since 1920. Thank you so much
10. ### math

In 1920, the record for a certain race was 45.5 sec. In 1970, It was 44.5 sec. Let R(t)=the record in the race and t=the number of years since 1920 Predict the record for 2003 and 2006

More Similar Questions