SOLUTION: alegbra equations find n 1,2,9,9,10,11,n range:13 median:9 mode:9 mean:8

range = largest value - smallest value

11 cannot be the largest value because then the range would be 11-1 or 10.

Therefore n has to be the largest value.

range = largest value - smallest value
   13 = n - 1
   14 = n

So if n=14 the range is 13.

The median and mode will still both be 9.

We have to check to make sure the mean will be 8, otherwise there'd
be no solution.

 1,2,9,9,10,11,n

becomes 

 1,2,9,9,10,11,14

and 



The mean is indeed 8, so n=14 is the solution.

Edwin