Answer:
Area of the garden is 700 square feet.
Explanation:
It is given that casey has backyard that is a 50 by 50 foot square. Area of yard is the product of its dimensions. So, the area of yard is

Let the area of the garden be x.
It is given that 420 out of 1500 points land inside the irregularly shaped garden. It means the proportion of these points is equal to the proportion of area.



The value of x is 700. Therefore the area of the garden is 700 square feet.