What is the mean and median for the length of 20.3 12.5 7.6 13.9 9.2 21.7 7.6 17.5 15.6 14.1

First list numbers in order
  7.6
  7.6
  9.2
12.5
13.9
14.1
15.6
17.5
20.3
21.7

find mean (the average number of all numbers listed) by adding everything(140) then dividing how many numbers there are(10):
140 divided by 10=14
mean=14

find median (literally the middle number in the set given):
but since there's two middle numbers (13.9 & 14.1), we find the mean (aka the average) of those numbers
28 divided by 2=14
median=14

The distance from point a to point c across the coordinate plane is aproxamatly 8.94 rounded to the nearest hundredth. you use a^2 + b^2 =c^2