For a screen that is 120 inches wide and the lens ratio is 2.5:1, how far should the projector be placed?

To determine the correct distance for placing the projector relative to the screen, you first need to understand the lens ratio given. The lens ratio of 2.5:1 indicates that for every inch of screen width, the projector must be placed 2.5 inches away.

In this case, the width of the screen is 120 inches. To find the required distance, you multiply the width of the screen by the lens ratio:

Distance = Screen Width x Lens Ratio

Distance = 120 inches x 2.5

Distance = 300 inches

This calculation shows that the projector should be placed 300 inches away from the screen to achieve the proper projection size based on the specified lens ratio. Thus, selecting the correct answer aligns with the calculation, confirming that the projector needs to be positioned at this distance for optimal image quality.