The scale factor of a yardstick (3 feet) to a ruler (1 foot) can be calculated by dividing the length of the yardstick by the length of the ruler.
In this case, the length of the yardstick is 3 feet, and the length of the ruler is 1 foot.
To find the scale factor, you divide the length of the yardstick by the length of the ruler:
Scale factor = Length of yardstick / Length of ruler
Scale factor = 3 feet / 1 foot
Scale factor = 3
Therefore, the scale factor of a yardstick (3 feet) to a ruler (1 foot) is 3. This means that every unit on the yardstick is equivalent to 3 units on the ruler.