To find the mode, it's the number that shows up the most in a set of numbers

[latex]1, 1,1,1, 2,4,4,6,7\\\\mean= \frac{1+1+1+1+ 2+4+4+6+7}{9} = \frac{27}{9} =3\\\\9:2=4.5 \ \ \ \Rightarrow\ \ \ mode=x_5=2\\---------------------\\\\1, 1,1,1, 2,3,3,4,6,8\\\\mean= \frac{1+1+1+1+ 2+3+3++4+6+8}{10} = \frac{30}{10} =3\\\\10:2=5 \ \ \ \Rightarrow\ \ \ mode= \frac{x_5+x_6}{2} = \frac{2+3}{2} =2.5[/latex]