Math Help Corner!

[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...

[Commander Sparx]

I'm good at Maths.

[Athos]

Then if you're good at math, would you be as so kind as to answer my post above?

[Commander Sparx]

I’m good at the number side of maths not the symbols sadly.

[Athos]

-.- There aren't even any symbols...

[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..

[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).

[Nyx]

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?

[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

[divinephoenix]

What topic in Stats is that?

[Athos]

Standard and Normal Distribution.

[divinephoenix]

ohh..ok..I dunno anything about that yet.

[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.

[Jade_Steel_Hawk]

Excellent!
I love you.

[Gaming Goddess]

Excellent!
I love you.

I don't blame you

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

[Hardcore]

What is two plus two? ):