Linear Functions

[bond007]

I need help with the problem listed below.

In 1920, the record for a certain race was 45.9 seconds. In 1930, it was 45.8 seconds. Let R (t)= the record in the race and t = 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 45.00 seconds.

 

[wjm11]

In 1920, the record for a certain race was 45.9 seconds. In 1930, it was 45.8 seconds. Let R (t)= the record in the race and t = 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 45.00 seconds.

Try plotting the data you are given in order to see what’s gong on. Plot R(t) on the y-axis, and plot t on the x-axis – but remember to subtract 1920 from the t values (because the problem said, “t = number of years since 1920.”

Now you have a graph with two points on it. It should be easy to figure out the equation of the line that passes through those points ( in the form y = mx + b, the slope-intercept form). First calculate the slope, then the y-intercept. That’s it.

Once you have the equation, parts b and c should be easy. Plug in 2003 and 2006 for t in part b. Plug in 45 for R(t) for part c.

 

[bond007]

Got it thank you.