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KrunaliG
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Given a list of 5 terms as: 5,10,15,20 and 25. A 6th Term X is added 11 Nov 2018, 23:37
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25% (medium)

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72% (01:08) correct 28% (01:26) wrong based on 233 sessions

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Given a list of 5 terms as: 5, 10, 15, 20 and 25. A 6th Term X is added in the list, what will be the value of X so that the standard deviation (S.D.) of the final list of 6 terms is minimum?

A. 20
B. 15
C. 30
D. 10
E. 0
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B
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KarishmaB
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Given a list of 5 terms as: 5,10,15,20 and 25. A 6th Term X is added Updated on: 04 Oct 2022, 00:27
Originally posted by KarishmaB on 11 Nov 2018, 23:45.
Last edited by KarishmaB on 04 Oct 2022, 00:27, edited 1 time in total.
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KrunaliG
Given a list of 5 terms as: 5,10,15,20 and 25. A 6th Term X is added in the list, what will be the view of X so that the standard deviation (S.D.) of the final list of 6 terms is minimum?

A - 20
B - 15
C - 30
D - 10
E - 0

Posted from my mobile device
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SD is minimised by having maximum terms at the mean.
The mean of 5,10,15,20, 25 is 15.

So the new number should be 15 too so that the SD does not increase but in fact decreases to get the minimum SD.

Answer (B)

Note: When you post a question, please ensure that you write it verbatim. Also, use the standard format of putting down options (A) (B) etc. A - makes one think that the numbers are negative.
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KrunaliG
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Given a list of 5 terms as: 5,10,15,20 and 25. A 6th Term X is added 11 Nov 2018, 23:48
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VeritasKarishma
KrunaliG
Given a list of 5 terms as: 5,10,15,20 and 25. A 6th Term X is added in the list, what will be the view of X so that the standard deviation (S.D.) of the final list of 6 terms is minimum?

A - 20
B - 15
C - 30
D - 10
E - 0

Posted from my mobile device


SD is minimised by having maximum terms at the mean.
The mean of 5,10,15,20, 25 is 15.

So the new number should be 15 too so that the SD does not increase but in fact decreases to get the minimum SD.

Answer (B)

Note: When you post a question, please ensure that you write it verbatim. Also, use the standard format of putting down options (A) (B) etc. A - makes one think that the numbers are negative.
Show more


Thank you so much for such a brief solution!
And yes will take care of the note too, thank you for the guidance.
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Given a list of 5 terms as: 5,10,15,20 and 25. A 6th Term X is added 12 Nov 2018, 00:20
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KrunaliG
VeritasKarishma
KrunaliG
Given a list of 5 terms as: 5,10,15,20 and 25. A 6th Term X is added in the list, what will be the view of X so that the standard deviation (S.D.) of the final list of 6 terms is minimum?

A - 20
B - 15
C - 30
D - 10
E - 0

Posted from my mobile device


SD is minimised by having maximum terms at the mean.
The mean of 5,10,15,20, 25 is 15.

So the new number should be 15 too so that the SD does not increase but in fact decreases to get the minimum SD.

Answer (B)

Note: When you post a question, please ensure that you write it verbatim. Also, use the standard format of putting down options (A) (B) etc. A - makes one think that the numbers are negative.


Thank you so much for such a brief solution!
And yes will take care of the note too, thank you for the guidance.
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Sure! Check out the link I have provided. You will find it useful.
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NamGup
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Given a list of 5 terms as: 5,10,15,20 and 25. A 6th Term X is added 16 Mar 2019, 08:21
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Why Option D is wrong ?
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KarishmaB
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Given a list of 5 terms as: 5,10,15,20 and 25. A 6th Term X is added Updated on: 05 Oct 2022, 22:44
Originally posted by KarishmaB on 22 Mar 2019, 05:59.
Last edited by KarishmaB on 05 Oct 2022, 22:44, edited 1 time in total.
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VeritasKarishma
KrunaliG
Given a list of 5 terms as: 5,10,15,20 and 25. A 6th Term X is added in the list, what will be the view of X so that the standard deviation (S.D.) of the final list of 6 terms is minimum?

A - 20
B - 15
C - 30
D - 10
E - 0

Posted from my mobile device


SD is minimised by having maximum terms at the mean.
The mean of 5,10,15,20, 25 is 15.

So the new number should be 15 too so that the SD does not increase but in fact decreases to get the minimum SD.

Answer (B)

Note: When you post a question, please ensure that you write it verbatim. Also, use the standard format of putting down options (A) (B) etc. A - makes one think that the numbers are negative.

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Responding to a pm:
Quote:

Why option D is wrong ?
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SD is minimised not by minimising the numbers but bringing them as close as possible to the average.
Here, the average is 15. The option closest to the average is 15. Hence it is correct.
Adding 10 instead will increase the SD.
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Given a list of 5 terms as: 5,10,15,20 and 25. A 6th Term X is added 29 May 2026, 14:44
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I just found the mean of all and if you see it would be 12.5, now 15 is the closest and would be having the least SD from the mean which is 2.5. Hence B is our answer
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