Question

What is the z-value of something that has an area of .8051 under the standard normal curve to its right?

Answer 1

`z`-score is `-0.86`.

Explanation:

We observe two facts:

(1) area to the right of `x` (for something) is `0.8051`

(2) area to the right of mean value (`z`-score `0`) is `0.5000`

Hence area between `z` and mean value is `0.3051`

As seen from tables, `z`-score for this `-0.86` (as it is to the left of mean value for which `z`-score is `0.00`).