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M is a certain set of numbers with an average (arithmetic
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17 Jul 2014, 06:02
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M is a certain set of numbers with an average (arithmetic mean) of 10 and a standard deviation of 2.5. Q is a subset of M consisting of 5 terms. Exactly 80% of the numbers in Q are located within 2 standard deviations from the average of M. Which of the following could Q be? A. {3, 4, 5, 10, 14} B. {3, 6, 7, 10, 12} C. {3, 5, 5, 10, 16} D. {1, 5, 7, 10, 18} E. {5, 6, 7, 10, 12}
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M is a certain set of numbers with an average (arithmetic
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17 Jul 2014, 06:16
goodyear2013 wrote: M is a certain set of numbers with an average (arithmetic mean) of 10 and a standard deviation of 2.5. Q is a subset of M consisting of 5 terms. Exactly 80% of the numbers in Q are located within 2 standard deviations from the average of M. Which of the following could Q be?
A. {3, 4, 5, 10, 14} B. {3, 6, 7, 10, 12} C. {3, 5, 5, 10, 16} D. {1, 5, 7, 10, 18} E. {5, 6, 7, 10, 12} Exactly 80% of the numbers in Q, so 4 out of 5 numbers are from 10  2*{SD} = 5 to 10 + 2*{SD} = 15. A. {3, 4, 5, 10, 14} > only 3 numbers are in this range. Discard. B. {3, 6, 7, 10, 12} > 4 numbers are in this range. OK. C. {3, 5, 5, 10, 16} > only 3 numbers are in this range. Discard. D. {1, 5, 7, 10, 18} > only 3 numbers are in this range. Discard. E. { 5, 6, 7, 10, 12} > all 5 numbers are in this range. Discard. Answer: B. Similar questions to practice: themeanandthestandarddeviationofthe8numbersshown98248.htmlthestandarddeviationofanormaldistributionofdatais99221.htmlavendingmachineisdesignedtodispense8ouncesofcoffee93351.htmlarithmeticmeanandstandarddeviationofacertainnormal104117.htmlthelifetimeofallthebatteriesproducedbyacertaincomp101472.html7075808590105105130130130thelistshownconsistof100361.htmlforacertainexamascoreof58was2standarddeviationsb128661.htmlacertaincharacteristicinalargepopulationhasa143982.htmltheresidentsoftownxparticipatedinasurvey83362.htmlthestandarddeviationofanormaldistributionofdatais99221.htmlthemeanandthestandarddeviationofthe8numbersshown98248.htmlifacertainsampleofdatahasameanof200anda127810.htmlgiventhatthemeanofsetais10whatistherangeoftwo141964.htmlifacertainsampleofdatahasameanof240andthevalue171843.htmlforacertainexamascoreof58was2standarddeviationsb128661.htmlCheck other Standard Deviation Questions in our Special Questions Directory. Hope this helps.
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Re: M is a certain set of numbers with an average (arithmetic
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30 Oct 2018, 06:11
10  2*{SD} = 5 to 10 + 2*{SD} = 15
please explain this .
Thanks



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M is a certain set of numbers with an average (arithmetic
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Updated on: 03 Jan 2020, 08:21
Ratnaa19 wrote: 10  2*{SD} = 5 to 10 + 2*{SD} = 15
please explain this .
Thanks If anyone else is confused: SD is 2.5. Being that we're looking for numbers that are outside 2 of the SD, it's 2.5 * 2 in both higher and lower from the mean i.e. 5 and 15 IMO the confusing part of that statement is the "to". Those are two separate statements. Within the 2 SD deviation we have 5, and then we have 15, or otherwise 5 to 15. The way I'd phrase it is as such: Low End: 10  2*{SD} = 5 High End: 10 + 2*{SD} = 15 Total range that's within 2 SD: 5 to 15. i.e. Ans. BHope that's helpful to anyone, I'm currently doing my best to avoid my actual job by answering random posts!
Originally posted by conormdr203 on 03 Jan 2020, 06:42.
Last edited by conormdr203 on 03 Jan 2020, 08:21, edited 1 time in total.



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Re: M is a certain set of numbers with an average (arithmetic
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03 Jan 2020, 07:57
goodyear2013 wrote: M is a certain set of numbers with an average (arithmetic mean) of 10 and a standard deviation of 2.5. Q is a subset of M consisting of 5 terms. Exactly 80% of the numbers in Q are located within 2 standard deviations from the average of M. Which of the following could Q be?
A. {3, 4, 5, 10, 14} B. {3, 6, 7, 10, 12} C. {3, 5, 5, 10, 16} D. {1, 5, 7, 10, 18} E. {5, 6, 7, 10, 12} Terms in Q = 5 80% *5 = 4 terms are located within 10 +5, i.e between 5 & 15. Only B{3,6,7,10,12} satisfy the condition. IMO B



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Re: M is a certain set of numbers with an average (arithmetic
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03 Jan 2020, 08:08
Ratnaa19 wrote: 10  2*{SD} = 5 to 10 + 2*{SD} = 15
please explain this .
Thanks Mean = 10 S. D. = 2.5 2 SD = 2*2.5 = 5 2 SD around mean is 10  5 to 10+5, i.e. between 5 and 15




Re: M is a certain set of numbers with an average (arithmetic
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03 Jan 2020, 08:08






