Alexxis S. answered • 05/31/21
A Love for Math, and a Passion to Help
If you have access to population data, as in the census, then you would calculate the population mean. Unfortunately, we do not usually have access to information from every person or subject. In this case, a sample is taken from the population and then the sample mean is calculated. The goal of the sample mean is to provide insight to a population.
Population mean: μ = ∑Xi / N
where μ is the population mean, ∑Xi is the sum of all values (X) in the population, and N is the number of subjects
Sample mean: xbar = ∑xi / n
where xbar (denoted as an x with a line above it) is the sample mean, ∑xi is the sum of all the values in the sample, and n is the number of subjects sampled
Alexxis S.
Yes you would use the sample mean. You would begin by adding the hourly rates, then dividing by the sample size (i.e. 20). You may have noticed that sample mean and population mean have a similar formula, the main thing that differs is the notation used but the calculation remains the same.05/31/21
Gary H.
Yes I did notice that, but it is still important to know whether you need to use sample and population mean. But yes thank you, your explanation was very helpful, I also posted a question about weighted mean, forgot to mention it here! Would really appreciate if you could check it out!05/31/21
Alexxis S.
Sure, I can take a look. What was your question titled or tagged under so it's easier for me to find?05/31/21
Gary H.
thank u so much again! :) The title is "urgent help weighted mean" someone had already answered it but they didn't show the formula or explain05/31/21
Gary H.
Thank you so much, great explanation! So for one of the questions I was given, it states "Twenty people in a company earn the following hourly rates." a) Find mean, median, mode, in this case I would use the sample mean because we are only given 20 people's hourly rates, but not the rest of the people of the company. Would that be correct? Although it would a lot easier if it stated 20 out of a certain # of people in a company earn the following hourly rates.05/31/21