Answer: the answer is c=27
Step-by-step explanation: to find the average you find the sum of all of the numbers and divide it by the number of answers that you have. so you will find 2+7+c and then divide by 3 in order to get 12. in order to find c you are going to do 12X3 which will give you an answer of 36. next add 7+2+9. subtract 36-9=27
