Need help w/statisitics homework!!!?

Question

Find the critical value for a two tailed test with alpha = 0.10. This is for a normal distribution. (find the z values)

Answer 1

The critical value for a z-test, two-tailed with alpha=0.1 is 1.645.

Answer 2

Hi,
Of course, the easiest way to do this is with a graphing calculator.
a) On a TI-83 Plus or TI-84, press 2ND, DISTR (the VARS key) and press 3 for invNORM.
b) Enter 1-.1, so that you have invNORM(1-.05). Press ENTER and the value 1.644 will be displayed.
The next best way is to use a table. Some books will have a short table for critical values from which you can read the critical value directly. Other books will have z-values for a normal distribution. You can find the critical value for these normal tables by finding the area to the right of the mean but outside the critical region and reading off the corresponding z-value. For example, to find a two-tailed for alpha = .1, find:
area = .5- .05
= .45
Look that up in the table (.4505 is a close as you can get in most tables) and you’ll find that area corresponds to 1.65.
FE