Math Help - mean calculation (advance type)

Let S be the sum of all items except for the two items in question. Then $\frac{S+92+8}{200}=50$. From here you can find $S$ and calculate $\frac{S+192+88}{200}$. Actually, $\frac{S+192+88}{200}=\frac{S+92+8}{200}+\frac{180} {200}=50.9$.