Let Z Denote a Random Variable Having a Standard Normal $P ( z < 1.28 )$

Essay

Let z denote a random variable having a standard normal distribution. Determine each
of the following probabilities. a) $P ( z < 1.28 )$
b) $P ( z < - 1.05 )$
c) $P ( z > - 2.51 )$
d) $P ( - 1.30 < z < 1.54 )$