Question

Calculate the meanof of prime number lying between 6 anand 20

Answer 1

Mean = Sum of observations / Number of observations
          = 7+11+13+17+19/5
          = 67/5
          =13.4

Answer 2

prime number lying 6 and 20 - 7, 11,13,17,19
mean = 7+11+13+17+19/5 [sum of observation /total number of observation
=    67/5  =13.4