5.设总体 sim N(75,100), X1,X2,X3是来自总体X的容量为3的样本,求:-|||-(1) (max {X)_(1),(X)_(2),(X)_(3))lt 85) ;-|||-(2) ( 60lt {X)_(1)lt 80} cup (75lt (X)_(3)lt 90} ) ;-|||-(3) ((X)_(1)+(X)_(2)leqslant 148).