\[\boxed{\mathbf{263.}}\]
\[Число\ орлов\] | \[0\] | \[1\] | \[2\] |
---|---|---|---|
\[Вероятность\] | \[\frac{1}{4} = 0,25\] | \[\frac{1}{2} = 0,5\] | \[\frac{1}{4} = 0,25\] |
\[EX = 0 \cdot \frac{1}{4} + 1 \cdot \frac{1}{2} + 2 \cdot \frac{1}{4} =\]
\[= \frac{1}{2} + \frac{1}{2} = 1.\]
\[= \frac{1}{4} + 0 + \frac{1}{4} = \frac{2}{4} = \frac{1}{2} = 0,5.\]
\[Ответ:0,5.\]