Question

There is a set of 100 observations with a mean of 46 and a standard deviation of 0. What is the value of the smallest observation in the set?
A. 73
B. 23
C. 0
D. 46

Answer 1

do you know what standard deviation means?

Answer 2

Not really. Couldn't find a clear enough example.

Answer 3

Well it is evident that you are studying this subject - and you need to get an understanding of the concept of what it means.
It is evident that you cannot begin to answer this question unless you know what SD is.

In short - it is a measure of how 'spread out' the observations are in a set of data.

If all the observations are very close to each other then they are all close to the mean, and the SD is small

If the observations are spread out from each other then they can have the same mean, but the SD is large.

I will tell you that if the SD=0 then ALL the observations have the SAME value.

Since you know the MEAN is 46 then you should be able to work out the minimum observation value.

However - you REALLY need to study your text, class or this:
http://www.mathsisfun.com/data/standard-deviation.html

and then come back to your exercises - you cannot do them if oyu don't understand what SD measures...