Vm = Volume of the men's basketball
Vm = (4/3)*pi*r^3
Vm = (4/3)*pi*(5)^3 ... diameter = 10 --> radius = 10/2 = 5
Vm = 523.598775598299 cubic inches
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Vw = Volume of the women's basketball
Vw = (4/3)*pi*r^3
Vw = (4/3)*pi*(4.5)^3 ... diameter = 9 --> radius = 9/2 = 4.5
Vw = 381.70350741116 cubic inches
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Difference in volume = Vm - Vw
Difference in volume = 523.598775598299 - 381.70350741116
Difference in volume = 141.89526818714 cubic inches
This result is approximate