The mean of the first five prime numbers is:

First, the five prime numbers are 2,3,5,7, and 11.

Number of observations =5

 Mean= $\frac{\mathrm{Sum} \mathrm{of} \mathrm{the} \mathrm{numbers}}{\mathrm{no} \mathrm{of} \mathrm{observations}}=\frac{2+3+5+7+11}{5}$

=$\frac{28}{5}=5.6$

Therefore, the mean of first five prime numbers is 5.6.