Z~ N(0,1)
Pr(-1<Z<2,1) = Pr(-1<Z<0) + Pr(0<Z<2,1) = 0.3413 + 0.4821 = 0.8234
Pr(-0,87<Z<1,54) = Pr(-0,87<Z<0) + Pr(0<Z<1,54) = 0.3078 + 0.4382 = 0.746
Pr(Z=1,54) = Pr(0 < Z < 1,54) - Pr(0 < Z < 1,53) = 0.4382 - 0.4370 = 0.0012 (para isolar o 1,54 é preciso tirar ou o valor anterior ou posterior, excluindo a possibilidade de acontecer qualquer outro evento)
Pr(Z > 2,5) = Pr (0 < Z) - Pr (0 < Z < 2,5) = 0.5 - 0.4938 = 0.0062
X~N(500,300)
Pr(X<500) = Pr (X < 0/300) = Pr (X < 0) = 0.5
Pr(400<X<710) = (-100/300 <X<210/300)= (-0.33 <X< 0.7) = Pr(-0,33<X<0) + Pr(0<X<0,7) = 0.1293 + 0.2580 = 0.3873
Pr(330<X<450) = (-170/300 <X<-50/300)= (-0.56 <X< -0.16) = Pr(-0,56<X<0) - Pr(-0,16<X<0) = 0.2123 - 0.0636 = 0.1487
Y~N(100,20)
Pr(50<Y<70) = (-50/20 <X<-30/20)= (-2.5<X< -1.5) = Pr(-2,5<X<0) - Pr(-1,5<X<0) = 0.4938 - 0.4332= 0.0606
Pr(105<Y<110) = (5/20 <X<10/20)= (0.25<X< 0.5) = Pr(0<X<0,5) - Pr(0<X<0,25) = 0.1915 - 0.0987 = 0.0928
Pr(Y>75) = Pr(Y>-25/20)= Pr (Y>-1,25) + Pr(Y>0) = 0.5 + 0.3944= 0.8944