To calculate the volume of a sphere, you use the formula:
\[ V = \frac{4}{3} \pi r^3 \]
First, we need to find the radius (r) of the sphere. The radius is half of the diameter:
\[ r = \frac{7 \text{ inches}}{2} = 3.5 \text{ inches} \]
Now, we can substitute the radius into the volume formula. We will use \(\pi \approx 3.14\):
\[ V = \frac{4}{3} \times 3.14 \times (3.5)^3 \]
Calculating \( (3.5)^3 \):
\[ (3.5)^3 = 3.5 \times 3.5 \times 3.5 = 42.875 \]
Now, substitute that value back into the volume formula:
\[ V = \frac{4}{3} \times 3.14 \times 42.875 \]
Calculating \( \frac{4}{3} \times 3.14 \):
\[ \frac{4}{3} \times 3.14 \approx 4.18667 \]
Now multiply that by \( 42.875 \):
\[ V \approx 4.18667 \times 42.875 \approx 179.594 \]
Finally, rounding to the nearest tenth:
\[ V \approx 179.6 \]
Thus, the volume of the sphere is approximately 179.6 cubic inches.