Let $\text{X}$ and $\text{Y}$ be two real-valued random variables with $\mathrm{E}(\mathrm{X})=1, \mathrm{E}(\mathrm{Y})=2, \mathrm{E}\left(\mathrm{X}^{2}\right)=4, \mathrm{E}\left(\mathrm{Y}^{2}\right)=9$, and $\mathrm{E}(\mathrm{XY})=0.9$, where $\text{E}$ denotes the expectation operator.
The value of $\alpha$ that minimizes $\mathrm{E}\left((\mathrm{X}-\alpha \mathrm{Y})^{2}\right)$ is $\_\_\_\_\_\_$
(Round off to one decimal place)
