Mean is just the average of all of them So... 5 + 4 + 18 + 19 + 12 + 20 + 12 + 12 = 102 Then you divide that number by the amount of numbers you have so 102 / 8 = 12.75 or rounding it up to 13
For median you have to first put them in order from smallest to largest. So 4 5 12 12 12 18 19 20 Then you have to find the middle number between them but in this case we have two... 12 and 12. Since they're the same number, the median is 12.