Answer:

Explanation:
First, we need to find the area of the circular garden.

The formula for the area of a circle is:

where:
- π is approximately 3.14
- r is the radius (half of the diameter)

So, in this case, the radius is:


Substitute the given values into the given formula:




Now we can use the given information to find out how much fertilizer Joni needs.

We know that she needs 2 teaspoons of fertilizer for every 25 square feet of garden.

So, we can set up a proportion:


Cross-multiplying, we get:


Simplifying, we get:




Joni will need approximately 12.3 teaspoons of fertilizer for her entire garden.