Final answer:
The y-intercept of the function represents the initial height of the candle, which is 9 units at the time it is first lit (x = 0 seconds).
Step-by-step explanation:
The y-intercept of the function f(x) = -0.55x + 9 represents the height of the candle the moment it is lit, which is when x = 0 seconds. In this context, the y-intercept is 9, meaning the candle starts off at a height of 9 units (assuming the units are consistent with those being used for measuring the candle, such as centimeters or inches). The negative coefficient of the x term in the equation, -0.55, indicates that the height of the candle decreases over time as it burns, at a rate of 0.55 units per second.