To find the price per foot of the ribbon, we start by converting the length from yards to feet. Since 1 yard equals 3 feet, we can convert the length as follows:
\[ 4 \text{ yards} \times 3 \text{ feet/yard} = 12 \text{ feet} \]
Next, we need to determine the cost per foot. The total cost of the ribbon is $3.12, and we now know that the total length is 12 feet. Therefore, we calculate the price per foot by dividing the total cost by the total length in feet:
\[ \text{Price per foot} = \frac{\text{Total Cost}}{\text{Total Length in feet}} = \frac{3.12}{12} \]
Now, performing the division:
\[ \text{Price per foot} = 0.26 \]
Thus, the price per foot of the ribbon is \($0.26\).