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Sats question

Posted: Apr 17, 2008 3:54am
by Athos
Okay. I finally opened my Stats book. I can't seem to figure out how to use this chart.
Positive Z-Score Chart
Negative Z-Score Chart
This chart is in reference to standard (normal) distributions, both positive and negative. (Same chart, but two pages.)

Here is what I understand thus far, the numbers under the z is the z-score and the numbers next to is is the probability or in other words the "area" under neath the curve. But then what in the name of all that is non-Lewis Carroll are those numbers which are about the areas? (I mean the one's that have: .00---.09)

Please help before my head explodes...

Re: Math Help Corner!

Posted: Apr 17, 2008 4:07am
by Commander Sparx
I'm good at Maths. 8)

Re: Math Help Corner!

Posted: Apr 17, 2008 4:08am
by Athos
Then if you're good at math, would you be as so kind as to answer my post above?

Re: Math Help Corner!

Posted: Apr 17, 2008 4:23am
by Commander Sparx
I’m good at the number side of maths not the symbols sadly.

Re: Math Help Corner!

Posted: Apr 17, 2008 4:32am
by Athos
-.- There aren't even any symbols...

Re: Math Help Corner!

Posted: Apr 17, 2008 4:33am
by Jade_Steel_Hawk
Is it due today?
I could probly figure it out after school....I think I have a general idea, but I can't explain it.. :?

Re: Math Help Corner!

Posted: Apr 17, 2008 4:39am
by Athos
No, it isn't due. I just need to get it done before Monday. I can't figure it out. In my Demystified book, it uses another chart. Thanks for the consideration Jade. (Anything will help).

Re: Sats question

Posted: Apr 17, 2008 10:43am
by Nyx
Athos wrote:Okay. I finally opened my Stats book. I can't seem to figure out how to use this chart.
Positive Z-Score Chart
Negative Z-Score Chart
This chart is in reference to standard (normal) distributions, both positive and negative. (Same chart, but two pages.)

Here is what I understand thus far, the numbers under the z is the z-score and the numbers next to is is the probability or in other words the "area" under neath the curve. But then what in the name of all that is non-Lewis Carroll are those numbers which are about the areas? (I mean the one's that have: .00---.09)

Please help before my head explodes...
Please no head exploding- this is easy. We're working on this too.

OK, so the number under the z is the z-score, and the other numbers, the .00-.09 are the numbers after the 10th's place. Round any long decimals to 2 places is what our teacher taught us.

Example: (try to follow along with your book when you read this- the school doesn't have a scanner to show you this)

Mean of some fish in the Atlantic=10 in.
Standard Deviation= 2
x= 7 (I'll go over finding higher and lower than.)
z=7-10/2 With me so far?
z=3/2 (reduced down)=1.5
So go to the back of the book and find the chart. Look for 1.50 on the positive side. 1.50 on the positive side should be .9332. That's the probability of 7 or higher. To find the probabibility of 7 or fewer, simply subtract .9332 from 1, or look up negative 1.50.

Were my directions helpful?

Re: Math Help Corner!

Posted: Apr 17, 2008 1:43pm
by Athos
But how do you know that it's the probability under the .00? Here's an example from my book.

The Beanstalk Club, a social orginization for tall people, has a requirement that women must be at least 70 in. (or 5 ft 10 in) tall. What percentage of women meet that requirement?

The book gives me the mean of women's heights as 63.6 in. The standard deviation is 2.5 inches.

So then the z-score is 2.56 ~ (2.6)

So, on the Positive Z-Score chart, for 2.6 there is: .9953, .9955, .9956, .9957, .9959, .9960, .9961, .9962,.9963, .9964.

The answer in the back of the book is .52

Re: Math Help Corner!

Posted: Apr 18, 2008 12:50am
by divinephoenix
What topic in Stats is that?

Re: Math Help Corner!

Posted: Apr 18, 2008 1:37am
by Athos
Standard and Normal Distribution.

Re: Math Help Corner!

Posted: Apr 18, 2008 1:55am
by divinephoenix
ohh..ok..I dunno anything about that yet.

Re: Math Help Corner!

Posted: Apr 18, 2008 6:21pm
by Gaming Goddess
On my math quiz today I just wrote a paragraph ranting about the restrictions of the English language and handed it in.


Just thought I'd say.

Re: Math Help Corner!

Posted: Apr 18, 2008 7:20pm
by Jade_Steel_Hawk
Excellent!
I love you. :D

Re: Math Help Corner!

Posted: Apr 19, 2008 11:21am
by Gaming Goddess
Jade_Steel_Hawk wrote:Excellent!
I love you. :D
I don't blame you 8)

Love you too Jadey-kins! <3 Let's get married.

Re: Math Help Corner!

Posted: Apr 22, 2008 2:33pm
by Hardcore
What is two plus two? ):