Gaussian-Distributed

[Starling]

Hello!

I need some help with these probability problems that I'm having trouble with. My teacher didnt really go over Gaussian-distribution so I am pretty lost.

Here are the problems:

*z is Gaussian-distributed*

a) Pr (z>1.43) = ?
b) Pr (z<o.79) = ?
c) Pr (z>-1.15) = ?
d) Pr (-1.31 <z<1.96) = ?
e) Pr (+1.31<z<1.96) = ?
f) For what c is Pr(z>c) = 3.8% ?

Any help woul be greatly appreciated! Thanks in advance!

 

[pka]

From the nature of these questions, you are asking for us to teach you the this topic. We are a help service not a tutorial. This is completely standard material and is in your text. Please read over it and then tell what you have done on these problems. What do you not understand how to do.

 

[tomato]

Sorry about that, I should have showed you the work I've done so far. Here's what I have:

*z is Gaussian-distributed*

a) Pr (z>1.43) = 7.64%
b) Pr (z<o.79) = 28.52%
c) Pr (z>-1.15) = STUCK ON THIS ONE
d) Pr (-1.31 <z<1.96) = 87.99%
e) Pr (+1.31<z<1.96) = 7.01%
f) For what c is Pr(z>c) = 3.8% STUCK ON THIS ONE

* I'm really not sure if my answers are correct. Thanks for any help anyone can offer! :wink:

 

[JakeD]

Sorry about that, I should have showed you the work I've done so far. Here's what I have:

*z is Gaussian-distributed*

a) Pr (z>1.43) = 7.64%
b) Pr (z<o.79) = 28.52% This looks like a typo. It should be 78.52%
c) Pr (z>-1.15) = STUCK ON THIS ONE
d) Pr (-1.31 <z<1.96) = 87.99%
e) Pr (+1.31<z<1.96) = 7.01%
f) For what c is Pr(z>c) = 3.8% STUCK ON THIS ONE

* I'm really not sure if my answers are correct. Thanks for any help anyone can offer! :wink:

They are OK, except for the typo. For the ones you're stuck on, try these calculators. For (f), use the second calculator.