Deviation of a data set.

[Naethiel]

I can't understand if i should use population or sample deviation formula , if we for example have the data set {-1,0,1,2} then do we use the deviation type of the population or sample formula to count the deviation?

 

[Dr.Peterson]

I can't understand if i should use population or sample deviation formula , if we for example have the data set {-1,0,1,2} then do we use the deviation type of the population or sample formula to count the deviation?

Please give some context. What do you mean by "deviation" (maybe "standard deviation"?), and what are you going to use it for? Where do the data come from? (That will determine whether they are a population or a sample.)

 

[Naethiel]

Yes i meant standard deviation, sorry for being unclear. Well im attending a lesson,introduction to statistics, in my university and my professor gave us an exercise where he simply asks us to calculate the standard deviation of this data set. I cant understand how im supposed to proceed not knowing if the data set is just a sample of a population , but the exercise doesnt specify anything other than what i already said. I dont know if im not understanding something correctly or if my professor wasnt clear enough.

 

[Dr.Peterson]

You'll need to ask your professor whether the data set is meant to be a population or a sample. But if you can't ask, just say that you are assuming it's a sample and use that formula. That's what most data you do this with will be. You may get extra credit for being aware of the issue!

 

[alicepe656]

The standard deviation of a data set describes the difference between the data in the set and their mean. The simpliest interpretation could be: "The higher deviation, the more differences there are in the data set". It is rarely non-zero. In fact, as far as I know, the only possibility for a data set to have zero deviation is when it contains only the same numbers.
You can find better expiation in ,..........

 

[Harry_the_cat]

You'll need to ask your professor whether the data set is meant to be a population or a sample. But if you can't ask, just say that you are assuming it's a sample and use that formula. That's what most data you do this with will be. You may get extra credit for being aware of the issue!

The standard deviation of a data set, be it a sample or a population, is calculated using the formula for n.

IF the data is a sample and IF you want to estimate the population standard deviation from that sample, then you use the formula with (n-1).

Dr P, This is my understanding. Please correct me if I am wrong.