Math Is Fun Forum

misdamike55

Member

Registered: 2007-08-10

Posts: 1

Hey Any Help Wit This One It Is A Good One BUS STATS

Z IS A STANDARD NORMAL VARIABLE find the value of Z in the following
A) THE AREA BETWEEN 0 AND Z IS 0.4678
B) THE AREA TO THE RIGHT OF Z IS 0.1112
C) THE AREA TO THE LEFT OF Z IS 0.8554
D)THE AREA BETWEEN -Z AND Z IS 0.754
E)THE AREA TO THE LEFT OF -Z IS 0.0681
F)THE AREA TO THE RIGHT OF -Z IS 0.9803

Last edited by misdamike55 (2007-08-10 06:32:16)

John E. Franklin

Member

Registered: 2005-08-29

Posts: 3,588

Re: Hey Any Help Wit This One It Is A Good One BUS STATS

This table might help a lot.

The curve is the same on left and right of zero.
Everything under the whole curve adds to 1.0, which is 100%.
Notice that at the bottom of the table, the area approaches 0.5 or 50%.
That is because they are just doing the area on the right side, not the left.
You can double 50% to get 100% for both sides.
In the table, let's find Z=1.42 .
How?
On the left margin, go down to 1.4, then go right to the first number for 1.40 which says ".4192" .
Then go to the right of this number to Z=1.41 which says "..4207" .
Now go right one more number to Z=1.42 which says ".4222" .
That ".4222" means that from the middle zero to the right where Z=1.42, that in between those two points under the curve is .4222 of the total area under the bell shape.
0.4222 is more than a third and less than a half you see right.
0.5 is half
0.3333 is just about one-third.
0.38 is close to 3 divided by 8, actually .375 .
Am I making any sense to you??

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