Step-by-step explanation:The surface area of a sphere (the shape of a baseball) is given by the formula, SA = 4 (pi) r^2. Given the circumference of the circle, you can solve for the radius.
The formula for circumference is C = 2 x pi x r.
So input 9 for C and solve. 9 = 2 x pi x r.
You will get that r is equal to about 1.43 in.
Now put that r value into the surface area equation: SA = 4 (pi) 1.43^2
You will get a surface area equal to about 25.7 in^2.
Now multiply that number by the number of baseballs you need to cover, 100.
I'll let you do that step by yourself since it's simple algebra and you're smart enough to figure it out ;)
