Answers

The Brainliest Answer!
2014-09-26T19:30:23+05:30
Mean of  first n natural numbers = (n+7)/3
 \frac{1+2+3+4+.......+n}{n}= \frac{n+7}{3}   \\ or,  \frac{n}{2n} . [2*1+(n-1).1] =  \frac{n+7}{3}
 \frac{n+1}{2} = \frac{n+7}{3}  \\ or,3n+3=2n+14
or, 3n-2n = 14-3
or,  n = 11
1 5 1
natural numbers start from 1 not 0