The diameter of a basketball rim is 18 inches. a standard basketball has a circumference of 30 inches. what is the distance between the ball and the rim in a shot in which the ball goes exactly in the center of the rim? show your work.

We know that
circumference=2*pi*r> r=circumference/(2*pi)
circumference=30 in
r=circumference/(2*pi)> 30/(2*pi)> 4.7746 in
the radius of a standard basketball is 4.77 in

the distance between the ball and the rim is equal to
radius of a basketball rim minus radius of a a standard basketball  
radius of a basketball rim =18/2> 9 in
radius of a a standard basketball=4.77 in


the distance between the ball and the rim=[9-4.77]> 4.23 in

the answer is
4.23 in

To solve this problem you must apply the proccedure shown below:

 1. You have the following information given in the problem above:

 - The diameter of a basketball rim is 18 inches.
 - A standard basketball has a circumference of 30 inches. 

 2. Therefore, the diameter of the standard basketball is:

 D=30 inches/π
 D=9.54 inches

 3. Therefore you have:

 (18 inches-9.54 inches)=8.45 inches on both sides

 4. Then, the distance the distance between the ball and the rim in a shot in which the ball goes exactly in the center of the rim, is:

 d=8.45 inches/2
 d=4.22 inches

 The answer is: 4.22 inches