Question

1.z=2

2.z=3.1

Answer 1

A standard normal curve has a mean $\mu =0$ and a standard deviation $\sigma =1$

The proportion of the standard normal curve given by a Z value is the probability value obtained from the standard distribution tables.

1. For $Z=2.0$, p value $=0.97725$

This represents the $97.725\%$ Percentile.

2. For $Z=3.1$, p value $=0.99903$

This represents the $99.903\%$ Percentile.