设随机变量X N(2,a平方)且P{2 < X < 4} = 0.3,则P{X < 0} ( )A.0.1 B.0.2 C.0.3 D.0.5

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设随机变量X N(2,a平方)且P{2 < X < 4} = 0.3,则P{X < 0} ( )A.0.1 B.0.2 C.0.3 D.0.5
设随机变量X N(2,a平方)且P{2 < X < 4} = 0.3,则P{X < 0} ( )
A.0.1 B.0.2 C.0.3 D.0.5

设随机变量X N(2,a平方)且P{2 < X < 4} = 0.3,则P{X < 0} ( )A.0.1 B.0.2 C.0.3 D.0.5
B x=2为中心,即P{X>2}=p{X

因为 x=2为对称轴
所以 P{X>2}=p{X<2}=0.5
又因为 P{0 因此 P{X<0}=p{X<2}-P{0