Answer:
3.1484030842439 inches. Also could be 9.891/π
Explanation:
The circumference of a circle is given by the equation C = 2πr
We know that the circumference is 9.891 inches, so substituting in, we get 9.891 = 2πr
We do not want to solve for r because that is the radius, and we want diameter, which is twice the radius. The equation already has a multiple of two so we can just rewrite the equation to:
9.891 = πd where d is the diameter
Solving for d, we divide both sides by π to get 9.891/π = d
We get 3.1484030842439 or just 9.891/π.