Final answer:
The estimated volume of air in a spherical balloon with a radius of 3 inches is calculated using the volume formula V = (4/3)πr³. Substituting the radius into the formula yields 36π cubic inches, corresponding to option a.
Step-by-step explanation:
To estimate the volume of air in a spherical balloon with a radius of 3 inches, we use the formula for the volume of a sphere, which is V = (4/3)πr³. Plugging in the radius of 3 inches into the formula, we get:
V = (4/3)π(3 inches)³
V = (4/3)π(27 cubic inches) = 36π cubic inches
Therefore, the estimate for the volume of air in the balloon is 36π cubic inches. This corresponds to option a.