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【单选题】
设$X\sim N(3,4)$,求P{2 < X ≤ 5}
A.
$\Phi(1)+\Phi(0.5)$
B.
$\Phi(1)-\Phi(-0.5)$
C.
$\Phi(0.5)+\Phi(0.25)$
D.
$\Phi(0.5)-\Phi(-0.25)$
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参考答案：
参考解析：
刷刷题刷刷变学霸
举一反三
【单选题】Which statement regarding (2, 4)-trees is incorrect? 关于(2, 4)-树，下列命题不正确的是：
A.
(2, 4)-trees are equivalent to red-black trees (2,4)-树等价于红黑树
B.
Each internal node has no more than 4 branches 每个内部节点的分支数不超过4
C.
Each internal node has no less than 2 branches 每个内部节点的分支数不小于2
D.
Each node has exactly 3 keys except for the root 除了根节点外，每个内部节点都恰好包含3个关键码
【单选题】The town finally _______ last week after being pounded with heavy artillery for more than two months.
A.
succeeded
B.
subscribed
C.
succumbed
D.
suspected
【单选题】函数$f(x) = \left\{ \begin{array}{l} 4x - 4,{\rm{ }}\quad \;\;\quad x \le 1, \\ {x^2} - 4x{\rm{ + 3, }}\quad x > 1 \\ \end{array} \right. $的图像与函数图像$ g(x)=\log_2 x $的图像交点个数是 ( ).
A.
4
B.
3
C.
2
D.
1
【单选题】设函数$f(x) = \left\{ \begin{array}{l} {2^{ - x}} - 1,{\rm{ }}\quad x \le 0, \\ {x^{\frac{1}{2}}}{\rm{, }}\qquad\quad \;x > 0, \\ \end{array} \right. $, 则不等式$ f(x)>1 $的解集是 ( ).
A.
$(-1,1) $
B.
$(-1,+\infty) $
C.
$( - \infty , - 2) \cup (0, + \infty ) $
D.
$( - \infty , - 1) \cup (1, + \infty ) $
【单选题】函数$ y = \frac{{\ln (1 + 3x)}}{{{x^2} - 3x + 2}} $的定义域为 ( ).
A.
$\left\{ {\left. x \right|x > - \frac{1}{3}} \right\}$
B.
$\left\{ {\left. {x \in R} \right|x \ne 1,x \ne 2} \right\} $
C.
$\left\{ {\left. x \right|x > - \frac{1}{3},x \ne 1,x \ne 2} \right\} $
D.
$\left\{ {\left. x \right|x > \frac{1}{3},x \ne 1,x \ne 2} \right\} $
【单选题】根据本题题干回答以下（1）（2）题已知离散随机变量\(X\)的分布列为(1)、\(Y=|X|\)，则\(P(Y=1)\)的值为
A.
\(\frac{7}{30}\)
B.
\(\frac{1}{15}\)
C.
\(\frac{1}{6}\)
D.
\(\frac{1}{5}\)