棍丰伦与散程统针」 解PXs=0"dx=1-e“-a92 PI<X≤2y=6"ax =e-0.1-e02=0.0861, p2<X≤3=品e"dr =e0.2-e0.3=0.0779,解 P X x x e d 10 1 { 1} 10 1 0 −   = 0.1 1 e − = − = 0.0952, P X x x e d 10 1 {1 2} 10 2 1 −    = 0.1 0.2 e e − − = − = 0.0861, P X x x e d 10 1 {2 3} 10 3 2 −    = e e 0.0779, 0.2 0.3 = − = − −