Answers

2014-03-07T15:42:07+05:30
Those no. which can be only divided by itself or 1 are called prime no.
the first 10 prime no. are
2  3   5   7  11  13  17  19  23   29
mean=2+3+5+7+11+13+17+19+23+29/10
=12.9
4 4 4
2014-03-07T15:42:59+05:30
First 10 prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29
sum of these numbers are 2+3+5+7+11+13+17+19+23+29 = 129
therefore, mean = sum of observation / no. of observation
                        = 129/10 = 12.9
1 1 1
1st10 prime numbers _ 2, 3, 5, 7, 11, 13, 17, 19, 23, 29
sum of these nos _ 2+3+5+7+11+13+17+19+23+29 = 129
mean = sum of observation / number of observation
= 129/10 = 12.9