SOLUTION: The height (in centimeters) of a candle is a linear function of the amount of time (in hours) it has been burning. When graphed, the function gives a line with a slope of −0.

Algebra.Com
Question 929132: The height (in centimeters) of a candle is a linear function of the amount of time (in hours) it has been burning. When graphed, the function gives a line with a slope of −0.3. See the figure below.
http://i.gyazo.com/edc311720eb8262dac67f4dcc2eb3f86.png
Suppose that the height of the candle after 15 hours is 24.5 centimeters. What was the height of the candle after 8 hours?
- - -
I get that the question is asking for 8 hours after the start of the burning, not 23 hours, but I just don't understand how to apply the slope here.

Answer by josgarithmetic(39617)   (Show Source): You can put this solution on YOUR website!
The quick way through is to know the slope-intercept form for a linear equation. Look at the graph showing x=0, y=b, the y-intercept. You don't know it, but at least you are given the slope and one data point.





substitute the known given point.



The equation for your line is


Just find y for x=8.



RELATED QUESTIONS

Suppose that the height (in centimeters) of a candle is a linear function of the amount... (answered by ankor@dixie-net.com)
Suppose that the height (in centimeters) of a candle is a linear function of the amount... (answered by josmiceli)
Suppose that the height (in centimeters) of a candle is a linear function of the amount... (answered by josgarithmetic)
Suppose that the height (in centimeters) of a candle is a linear function of the amount... (answered by josgarithmetic)
Suppose that the height (in centimeters) of a candle is a linear function of the amount... (answered by josgarithmetic,ikleyn)
Suppose that the height (in centimeters) of a candle is a linear function of the amount... (answered by josmiceli)
Suppose that the height (in centimeters) of a candle is a linear function of the amount... (answered by josgarithmetic)
Suppose that the height (in centimeters) of a candle is a linear function of the amount... (answered by ikleyn)
Suppose that the height (in centimeters) of a candle is a linear function of the amount... (answered by josgarithmetic,Boreal)
Suppose that the height (in centimeters) of a candle is a linear function of the amount... (answered by ikleyn,josgarithmetic)