Question

The table lists selected values of Sam's walking speed, in kilometers per hour (km/h), and his corresponding

pulse, in beats per minute (bpm). There is a linear relationship between Sam's speed, x, and his pulse, f(x).
Which of the following equations describes f(x)?

Answer 1

9514 1404 393

Answer:

(C) f(x) = 5x +57

Explanation:

Heart rate increases as speed increases, so only equations with a positive x-coefficient are of interest. It is pretty easy to see that ...

f(x) = x+57

doesn't give ...

f(4) = 77

However, the other reasonable choice is ...

f(x) = 5x +57

which does give f(4) = 77.