Question

Consider the standard normal distribution with mean  = 0, and standard deviation  = 1

a. What is the probability that an outcome z is greater than 2.20? b. What is the probability that z is less than 1.1? c. What is the probability that z is between -1.03 and 0.84? d. What value of z cuts off the upper 23% of the standard normal distribution? e. What value of z cuts off the lower 18% of the standard normal distribution?

Answer 1

a) = P(Z > 2.20   ) = P( Z <   -2.200   ) =    0.0139   (answer)

b) =P(Z < 1.10   ) =   0.8643   (answer)

c) P (    -1.030   < Z <    0.840   )                       
= P ( Z <    0.840   ) - P ( Z <   -1.03   ) =    0.7995   -    0.1515   =    0.6480   (answer)

d) Z value at    0.77   =   0.7388   (excel formula =NORMSINV(   0.77   ) )

e) Z value at    0.18   =   -0.9154   (excel formula =NORMSINV(   0.18   ) )