Answer:
10 feet
Explanation:
To find out the size of the base of the final version, we need to determine the scaling factor between the model and the final version.
Given that 1/4 of an inch on the model corresponds to 6 feet on the final version, we can set up the following proportion:

To solve for x, we cross-multiply:

Now, let's simplify the equation:

To eliminate the fraction, we can multiply both sides of the equation by 4:

Therefore, the base of the final version will be 10 feet.