Explanation:

Mean =sum of number/total number

(7+5+5+2+7+6+5+3+7+6)/10
=53/10=5.3
For median,
First of all we have to arrange the
data in ascending or descending order
2,3,5,5,5,6,6,7,7,7
For n= even, median = average of
nth term /2 +(n/2 + 1)th term
=(5+6)/2=5.5