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Standard deviation

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Standard deviation

by lordpapi63 » Fri Jul 11, 2008 7:04 pm
the arithmetic mean and standard deviation of a certain normal distribution are 13.5 and 1.5 respectively. What value is exactly 2 standard deviations less than the mean?

10.5

11.0

11.5

12.0

12.5
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by john1234 » Fri Jul 11, 2008 7:12 pm
The answers is A.
10.5
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by shrikantkamble » Fri Jul 11, 2008 8:25 pm
Arithmatic mean A.M. = 13.5
S.D = 1.5
2 standard deviation less than mean.
= 13.5 - 2*1.5
= 13.5 - 3.0
=10.5

Answer A 10.5 is correct answer
Thanks & Regards,
Shrikant
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