The average of a list of numbers is determined by adding all the numbers up, and then dividing by how many numbers there were (In other words, the sum of all the numbers divided by the amount of numbers). 63 + 68 + 64 + 54 + 51 = 300. There are 5 numbers total. 300 (sum of all numbers)/5 (amount of numbers) 300/5 = 60. Your average is 60.
