Final answer:
The resistance of the lightbulb is approximately 394.453 Ω.
Step-by-step explanation:
To find the resistance of a lightbulb, we can use the formula:
R = (V^2) / P
where R is the resistance, V is the voltage, and P is the power. In this case, the voltage is the maximum voltage of 172 V and the power is 75.0 W. Plugging in these values, we get:
R = (172^2) / 75.0 = 394.453 Ω
Therefore, the resistance of the lightbulb is approximately 394.453 Ω.