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#1 2011-04-07 07:55:27
- survival
- Member
- Registered: 2011-04-03
- Posts: 655
Standard Normal Curve
Thank you in advance!
Find the percentage of area under the standard normal curve that is specified:
Between z=0 and z = -04.
The percentage of area under the standard normal curve is_______%
Second problem:
Find the percentage of area under a normal curve between the mean and -0.08 deviations from the mean.
Percentage from the area under the normal curve between the mean and -.08 standard deviations from the mean is ____%
Third problem:
Find the percentage of the total area under the standard normal curve between the following z scores:
z= - 1.4 and z = -0.65 is ____%.
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#2 2011-04-07 08:46:32
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Standard Normal Curve
Hi;
Let me see what you know. Here is a graph of z score percentages and the Standard Normal curve.
Can you now answer the first problem?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#3 2011-04-07 09:31:30
- survival
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- Registered: 2011-04-03
- Posts: 655
Re: Standard Normal Curve
Oh wow! I will have to look at this one to see how it's solved. I don't know how you did that.
Thanks much.
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#4 2011-04-07 10:15:43
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Standard Normal Curve
Hi survival;
I just copied the table, so I have not done anything yet. Can you get the answer for the percentage or do you need help?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#5 2011-04-07 12:12:32
- survival
- Member
- Registered: 2011-04-03
- Posts: 655
Re: Standard Normal Curve
The answer was 29%. I still don't understand it. I get half the problem right and there at the last part do something wrong.
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#6 2011-04-07 12:14:33
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Standard Normal Curve
Hi;
Between z=0 and z = -04.
How are you getting 29% ? That says from 0 to -4 sd.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#7 2011-04-07 12:20:56
- survival
- Member
- Registered: 2011-04-03
- Posts: 655
Re: Standard Normal Curve
I am only taking these 3 last units of math because it is required. I grad. with associate of fine arts degree in about four wks. Then onto a four yr. university where my major will be Creative writing/Journalism. They did not have a major in Journalism here, which is my thing.
I put all required math till last, so this is basically why i am against the wall. I passed Algebra last semester. Then the last required 3 this semester should do me in. I get by with it and may come out with a B, but that will be the best I can pull off in one of them.
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#8 2011-04-07 12:25:16
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Standard Normal Curve
Hi;
Will they have math courses at your new university?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#9 2011-04-07 12:42:06
- survival
- Member
- Registered: 2011-04-03
- Posts: 655
Re: Standard Normal Curve
The first one, .4 i think it was .0155, later i had a problem with .8 that was 29%.
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#10 2011-04-07 12:43:17
- survival
- Member
- Registered: 2011-04-03
- Posts: 655
Re: Standard Normal Curve
Don't know. I will go in as a junior so will have to see.
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#11 2011-04-07 12:48:04
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Standard Normal Curve
Most likely there will be! So do not throw your math brain away just yet.
Now, please bear with me. How do you get 29%. Do not be shy, just tell me.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#12 2011-04-07 13:08:01
- survival
- Member
- Registered: 2011-04-03
- Posts: 655
Re: Standard Normal Curve
I didn't know how to use the graph you posted, so I just kept plugging away with the calculator. Thanks so much.
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#13 2011-04-07 13:21:39
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Standard Normal Curve
Hi survival;
That is no problem I will show you how.
Okay, just take a look at the graph. Do you see from 0 to -1 standard deviations it says 34.13 %. And from -1 to -2 it says 13.59%. From - 2 to -3 it says 2.14% and finally from -3 to -4 it says .13 %. You just have to add them up!
34.13 + 13.59 + 2.14 + .13 = ? %
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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