Given a dataset $X$ with $n=10$ observations, where the sum $\sum_{i=1}^{10} x_i = 100$ and the sum of squares $\sum_{i=1}^{10} x_i^2 = 1200$. If we transform the data by $y_i = 2x_i + 5$, what is the variance $\sigma_y^2$ of the new dataset?