Question

I am unsure whether this its asking for sample or population standard deviation.

Find the mean, standard deviation, and five number summaries for each type of M&M (plain and peanut) for the number of M&Ms in each bag.

Type	Number
Peanut	8
Peanut	8
Peanut	7
Peanut	6

This is a snippet of data since I can't find the whole thing. Basically, I am given the type and number. If its asking for the standard deviation of peanut m&ms, would I use sample or population?

Answer 1

Here, I would recommend you to use population standard deviation, ​​​​​.

When we want make inference about the population and we were given a sample, then we need to find sample standard deviation, s using the given sample data. If we want to know the standard deviation of the sample alone without making inference about the population, we need to find population standard deviation, because our sample is considered as population then.

Here, in this case, it is asked to find mean, standard deviation, and five number summaries which usually happens for population data or when sample is considered as population, i.e., not making inference about population. So, it is better to use the population standard deviation formula.

Population standard deviation, ​​​​​​

Sample standard deviation, s =​​​​​​

However, if you are making inference about the population of all peanut m&ms, then you have to use sample standard deviation formula. If you are unsure, use population standard deviation formula for the same reason above.