Final answer:
To properly scale down the inches so that all available grid squares are used to represent the perimeter outline for a blueprint, calculate the scale factor by dividing the perimeter measurements by the number of squares on the grid paper. Each square on the grid paper represents 0.1258 inches horizontally and 0.1008 inches vertically.
Step-by-step explanation:
To properly scale down the inches so that all available grid squares are used to represent the perimeter outline for a blueprint, we need to calculate the scale factor.
The given grid paper has forty 1/4 squares across and thirty 1/4 squares down. Therefore, the total number of squares on the paper is 40 x 30 = 1200.
The perimeter of the blueprint is 151 inches by 121 inches. To find the scale factor, divide the perimeter measurements by the number of squares on the grid paper: 151/1200 = 0.1258 inches per square and 121/1200 = 0.1008 inches per square.
Therefore, to properly scale down the inches, each square on the grid paper represents 0.1258 inches horizontally and 0.1008 inches vertically.