Question

How do you find the value of `z` so that the area under the standard normal curve from 0 to `z` is 0.4049?

Answer 1

`z ~~ 1.310`

Explanation:

If you want the area between 0 and `z` to be 0.4049, then the total cumulative area up to `z` will be 0.4049 + 0.5 = 0.9049. I used stat tables to find the `z` value for 0.9049, which is approximately 1.310.

This stats table is taken from the OCR A-Level Mathematics List of Formulae and Statistical Tables booklet:
http://www.ocr.org.uk/images/70824-datasheet-examination-formulae-and-statistical-tables.pdf