Final answer:
The dimensions of the actual garden in feet are 16 by 24 feet.
Step-by-step explanation:
To find the dimensions of the actual garden in feet, we need to use the given scale factor. The sketch of the garden measures 4 by 6 inches, and the scale factor is 1 inch = 4 feet.
So, we can multiply each dimension of the sketch by the scale factor to find the actual dimensions of the garden.
For the length, 4 inches * 4 feet/inch = 16 feet. And for the width, 6 inches * 4 feet/inch = 24 feet.
Therefore, the dimensions of the actual garden are 16 by 24 feet, which is option c).