Question

Suppose that the height (in centimeters) of a candle is a linear function of the amount of time (in hours) it has been burning. After 15 hours of burning, a candle has a height of 19 centimeters. After 32 hours of burning, its height is 12.2 centimeters. What is the height of the candle after 28 hours?

Answer 1

24.2 centimeters

Explanation:

for height = f(time)

let x be the value of the height at 28hours

solving linearly

(28 - 15)/(32 - 15) = (x - 19)/(12.2 - 19)

solving we have

13/17 = (x - 19)/6.8

0.7647 = (x - 19)/6.8

cross multiplying,

x - 19 = 5.2

x = 5.2 + 19 = 24.2centimetres