Step-by-step explanation: ok so first to find the mean you add all the numbers then divide by how many numbers there is so basically 18 plus 15 plus 20 plus 15 then divide by 4 because there is 4 numbers and once you do that it is 17
The answer is 4pi because the formula to find the circumference is C = 2 pi r. this question is asking for the terms of pi which means you remove the pi from the formula and solve it with out it. the radius is 2 because of the 2 units on the graph is halfway of the circle. you would just multiply 2 x 2 and get 4. after that you put the pi on the end of the 4. so the answer is C. (4pi)