Assume Z has a normal distribution, use the proportions of area under the normal curve table to calculate the following:

Question

Assume Z has a normal distribution, use the proportions of area under the normal curve table to calculate the following:

1. P(z > 1.1 or z < 2.3) =
2. P(z > 1.1 and z < 2.3) =

Answer 1

1. P(z > 1.1 or z < 2.3) = 1 (since this is a sure event or you consider it as the union of areas which is the total area under the normal curve)
2. P(z > 1.1 and z < 2.3) = P(1.1 < z < 2.3)=P(z < 2.3) - P(z<1.1)= .9893 - .8643 = 0.1250 = 12.5%