概车纶与款理统外 (1)P{X>1000}=1-P{X≤1000} =1-F(1000) 1 =e2≈0.607. (2)P{X>2000X>1000} P{X>2000,X>1000} = P{X>1000} P{X>2000} P{X>1000}(1) P{X  1000}= 1− P{X  1000} = 1− F(1000) e 0.607. 2 1 =  − (2) P{X  2000X  1000} { 1000} { 2000, 1000}    = P X P X X { 1000} { 2000}   = P X P X