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Weird One

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new_n_lost
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08/27/07 - 06:45 AM

A particular association determines membership on the basis of members IQ scores. Only those persons who have documented IQ scores at least 2 standard deviations above the mean on the Wechsler Adult Intelligence Scale (WAIS) are eligible for admission. Of a group of 200 people randomly selected from the population at large, how many would be eligible for membership to this society?

A. 1
B. 2
C. 3
D. 4
E. 5

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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."

yoga
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08/27/07 - 07:40 AM

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we are all in the gutter but some of us looking at the stars

edie
I can, and I will.
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08/27/07 - 09:11 AM

po
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08/27/07 - 09:52 AM

edie wrote:
E

assuming Normal distribution=
[got first aid help for this one]
1 SD=68%
2SD=95%
3SD=99.7%
so, 95%out of 200 would mean 10[5 lower end and another 5 at the higher end]people scoring above and below 2SD=>they are asking for how many above 2SD would be eligible.

hope4dabest
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08/27/07 - 09:53 AM

hope4dabest
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08/27/07 - 09:55 AM

OMG!! Never thought this way..thanks

po
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08/27/07 - 10:04 AM

dont worry I think we come under 95%,got wrong then learnt the right way nod

hope4dabest
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08/27/07 - 10:16 AM

po wrote:
dont worry I think we come under 95%,got wrong then learnt the right way nod

...no worries i will be also happy with that

edie
I can, and I will.
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08/27/07 - 02:01 PM

Yep, FA's got it, also check out biostats section of KLN Behavioral Science and know the distribution curve and SD correlations COLD smiling face

new_n_lost
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08/28/07 - 05:14 PM

#10

edie wrote:
E

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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."

new_n_lost
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08/28/07 - 05:14 PM

#11

The correct answer is E.

95% of a normally distributed population will fall between plus or minus 1.96 standard deviations from the mean. Since the population is normally distributed with regard to IQ, this means that approximately 2.5% of the population will have IQ scores 2 standard deviations or more above the mean, and 2.5% of the population will have IQ scores 2 standard deviations or more below the mean. 2.5% of 200 people is 5 people

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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."

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