Probability survey, from OG free test

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Probability survey, from OG free test

by isisalaska » Sat Feb 10, 2007 2:37 pm
In a survery of 248 people, 156 are married, 70 are self-employed, and 25 of those who are married are self-employed. If a person is to be selected randonly what is the prob. is self-emplyed BUT NOT MARRIED?
a) 1/8
b) 4/31
c) 117/248
d) 1/4
e) 31/117

Please explain the steps to reach a) 1/8
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isisalaska wrote:In a survery of 248 people, 156 are married, 70 are self-employed, and 25 of those who are married are self-employed. If a person is to be selected randonly what is the prob. is self-emplyed BUT NOT MARRIED?
a) 1/8
b) 4/31
c) 117/248
d) 1/4
e) 31/117

Please explain the steps to reach a) 1/8
Are u sure that this text is correct?

According the statement we have 45 chances (70 - 25) in 248 possibilities. so 45/248

I didnt get it.

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by Stacey Koprince » Sun Mar 11, 2007 10:09 pm
I'm also getting 45/248 with the given numbers. Isis, can you double check the text? Thanks!
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Re: Probability survey, from OG free test

by dsuna » Sat Mar 24, 2007 8:34 pm
isisalaska wrote:In a survery of 248 people, 156 are married, 70 are self-employed, and 25 PERCENT of those who are married are self-employed. If a person is to be selected randonly what is the prob. is self-emplyed BUT NOT MARRIED?
a) 1/8
b) 4/31
c) 117/248
d) 1/4
e) 31/117

Please explain the steps to reach a) 1/8
There was a missing word in the text, 25 is a percent of the married and self employed

25% of married and self employed means 25% of 156 = 39
70 self employed minus 39 married & self employed = 31 self employed and Not married
the probability is 31/248 = 1/8

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by Cybermusings » Tue Mar 27, 2007 4:45 am
Thanks Dsuna