To find the volume of a sphere (which is the shape of the piñata), we can use the formula:
\[ V = \frac{4}{3} \pi r^3 \]
Where \( V \) is the volume and \( r \) is the radius of the sphere.
Given that the diameter of the piñata is 18 inches, we can find the radius:
\[ r = \frac{\text{diameter}}{2} = \frac{18 \text{ inches}}{2} = 9 \text{ inches} \]
Now, we can substitute the values into the volume formula using \( \pi \approx 3.14 \):
\[ V = \frac{4}{3} \times 3.14 \times (9)^3 \]
Calculating \( 9^3 \):
\[ 9^3 = 729 \]
Now substitute that back into the volume formula:
\[ V = \frac{4}{3} \times 3.14 \times 729 \]
Now compute \( \frac{4}{3} \times 3.14 \):
\[ \frac{4}{3} \times 3.14 = 4.1867 \]
Then calculate the volume:
\[ V \approx 4.1867 \times 729 \approx 3,055.4 \]
Finally, rounding to the nearest tenth:
\[ V \approx 3,052.1 \text{ cubic inches} \]
Therefore, the volume of the piñata is approximately 3,052.1 inches³.