19. Length of brand P of pencils has a variance and standard deviation of 28 and 70 while brand Q’s is 40 and 80. Which brands length is closer to the mean and what is its coefficient of variance?
A. P,40
B. P,50
C. Q,40
D. Q,50

Question

19.	Length of brand P of pencils has a variance and standard deviation of 28 and 70 while brand Q’s is 40 and 80. Which brands length is closer to the mean and what is its coefficient of variance?
A.	P,40
B.	P,50
C.	Q,40
D.	Q,50

anonymous · Answer

pls help for this prob

anonymous · Answer

Question is pretty old but I have some comments. The first is that std dev is defined to be the square root of the variance. So I don't see how the values given could be correct. Second, with a given variance, it would be impossible to know the mean without the original data. Since http://en.wikipedia.org/wiki/Coefficient_of_variation is variance / mean, I don't think the problem can be solved from this data.

amistre64 · Answer

smaller sds are packed closer to the mean, i recall that much

amistre64 · Answer

since 70 < 80; i would go with P to narrow the odds

mathmate · Answer

It's unlikely that the question supplies both variance and standard deviation.  Perhaps you could check if there is a typo, and "standard deviation" was meant to the the mean.