Mean - find the sum of that set of numbers then divide your answer by the total of numbers in the set. E.g if the numbers are 10, after finding the sum you divide it by 10 since the numbers are ten.
Median - first arrange the numbers from small to big than find the middle number and if they are two like when the numbers are of an even number than you add the two numbers and divide answer by 2.
Range - arrange the numbers from small to big than minus the smallest one from the biggest number.
Am not sure about the last one but I hope I was able to help you with this three.
