Problema Solution

In 1930, the record for the 400-m run was 46.8 seconds. In 1970, it was 43.8 seconds. Let R(t)=the record in the 400-m run and t=the number of years since 1930. Find a linear function that fits the data. (R(t)=mt+b)

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In 1930, the record for the 400-m run was 46.8 seconds. In 1970, it was 43.8 seconds. Let R(t)=the record in the 400-m run and t=the number of years since 1930. Find a linear function that fits the data. (R(t)=mt+b)

Solution:

Slope = (43.8-46.8)/(1970-1930) = -3/40 = -0.075

When t=0, y=46.8

So the linear function is

R(t)=-0.075t+46.8