Final answer:
The scale factor for enlarging a 4" by 10" photograph to a 1 ft. by 2.5 ft. poster is 3, after converting feet to inches for consistent units of measurement.
Step-by-step explanation:
To find the scale factor of a photograph that is enlarged from 4 inches by 10 inches to 1 foot by 2.5 feet, we need to first convert all measurements to the same unit, typically inches. There are 12 inches in a foot, so 1 foot is 12 inches and 2.5 feet is 30 inches.
Then, we can compare the new dimensions to the original dimensions. We can calculate the scale factor using either the width or the height, as the enlargement must keep the same proportions.
Using the width:
- Original width = 4 inches
- New width = 12 inches
- Scale factor for width = New width / Original width = 12 / 4 = 3
Using the height:
- Original height = 10 inches
- New height = 30 inches
- Scale factor for height = New height / Original height = 30 / 10 = 3
The scale factor for enlarging the photograph to a poster is 3.