Statistics

Let the mean and variance of 12 observations be \(\frac{9}{2}\) and 4 respectively. Later on, it was observed that two observations were considered as 9 and 10 instead of 7 and 14 respectively. If the correct variance is \(\frac{m}{n}\), where \(\mathrm{m}\) and \(\mathrm{n}\) are coprime, then \(\mathrm{m}+\mathrm{n}\) is equal to :