CFA Practice Question

CFA Practice Question

The population of potatoes harvested during a year is very large (many millions). Suppose potato weights have a lognormal distribution. The mean weight of a potato is 0.2511 lbs, and the standard deviation is 0.0752 lbs. Consider a sample of size 100. Prior to the sample being taken, the mean of the sample is a random variable. What is the standard deviation of this random variable?
A. 0.029258
B. 0.075200
C. 0.006267
Explanation: From CLT, we know the sample mean is normally distributed around the population mean.

User Contributed Comments 5

User Comment
Marleni how do you get .006267?
chantal All I can think of is that the population mean will have a much lower standard of deviation simply because it has no sample error. Assuming a 5% max error, ie 2.5% on each side you will get a standard deviation of 0.0063.

???
kazec1 Shouldn't the std simply be 0.0752/10??
safash So I'm assuming everybody who attempted this got it wrong!!!!!
seanj951 In what way is that an explanation for how to get 0.006267?
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