How do I find $\displaystyle P(Z \le -0.9)$? I think it is the same as $\displaystyle P(Z \ge 0.9)$. So then, do I just find $\displaystyle \Phi$0.9 and subtract it from 1? (1-0.8159=0.1841)

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- Jun 1st 2009, 05:12 PMjennifer1004normal distribution to approximate
How do I find $\displaystyle P(Z \le -0.9)$? I think it is the same as $\displaystyle P(Z \ge 0.9)$. So then, do I just find $\displaystyle \Phi$0.9 and subtract it from 1? (1-0.8159=0.1841)

- Jun 1st 2009, 05:17 PMpickslides
(Nod)

- Jun 1st 2009, 05:57 PMmatheagle
I really like these online stat calculators.

They give p-values and they have all kinds of densities, t, F...

Free Cumulative Area Under the Standard Normal Curve Calculator

Plugging in -.9 give a probability of .1840601 and you can see a pretty picture too. - Jun 1st 2009, 07:29 PMjennifer1004
Thank you so much! That calculator definitely will come in handy.

- Jun 1st 2009, 08:09 PMmatheagle
Notice that there are many different distributions on the home page.

Also when you learn about p-values you will look back and really appreciate my comments today.