Answer:
17.8 cm
Step-by-step explanation:
In the 17 hours between heights of 18.6 cm and 15.2 cm, the candle lost 3.4 cm in height. That is, the height decreased at the rate of ...
(-3.4 cm)/(17 h) = -0.2 cm/h
In the 4 hours between 12 hours and 16 hours of burning time, the candle will have changed its height by (4 h)(-0.2 cm/h) = -0.8 cm.
The height at 16 hours of burning is then 18.6 cm -0.8 cm = 17.8 cm.
9^-2 = 1/81 or 0.0123
When there is a negative in front of the exponent it makes a fraction. It is usually just 1/the number it equals if it were positive.
