a) P(Z < 1.000Â Â ) =Â Â
0.8413 (answer)
b)Z value at   0.75  = Â
0.674Â Â (excel formula =NORMSINV(Â Â
0.75Â Â ) )
answer: 0.674
c)P(Z > d) = 0.83
P(Z≤d) = 1-0.83 = 0.17
Z value at   0.17  = Â
-0.954Â Â (excel formula =NORMSINV(Â Â
0.17Â Â ) )
answer: -0.954
d)proportion=Â Â 0.9500Â Â Â Â Â
        Â
  Â
proportion left   0.0500  is equally
distributed both left and right side of normal
curve        Â
     Â
z value at  0.025  = ± Â
1.960Â Â (excel formula =NORMSINV(Â Â
0.05Â Â / 2 ) )Â Â
so, value of b = 1.96
