概率伦与款理统外 由F(x)=P{X≤x, 得PXs2=r= 吗x=F-r鸣} P{2≤X≤3}=F(3)-F(2)+P{X=2 =1-3+13 42-41 由 F(x) = P{X  x}, , 4 1 = ) 2 3 ) ( 2 5 } ( 2 5 2 3 P{  X  = F − F , 2 1 4 1 4 3 = − = P{2  X  3} = F(3) − F(2) + P{X = 2} 2 1 4 3 = 1 − + . 4 3 = ) 2 1 } ( 2 1 得 P{X  = F