Question:

Mean and variance of 12 observations are 9 and $\frac{4}{2}$ (note: variance=$\frac{4}{2}$). Two values 9 and 10 were wrongly noted instead of 7 and 14. If correct variance is $\frac{m}{n}$ with $\gcd(m,n)=1$, then $m+n$ is equal to