Final answer:
The actual length of the mattress is calculated by multiplying the scale length of 6.25 inches by the scale factor of 12, resulting in 75 inches as the actual length.
Step-by-step explanation:
To find the actual length of the mattress when the scale factor is 1:12, and the scale length is 6.25 inches, we need to multiply the scale length by the scale factor. The scale factor 1:12 means that one unit of measurement in the model is equivalent to twelve units in the actual object. Therefore, we write the proportion: 1 inch (model) : 12 inches (real life).
Now we solve for the actual length using the scale length (6.25 inches):
- Model Length x Scale Factor = Actual Length
- 6.25 inches x 12 = Actual Length
- 75 inches = Actual Length
Thus, the actual length of the mattress is 75 inches.