The ratio wherein the addition of the values to the number of the value is a population mean – if the possibilities are equal. A population mean include each element from the set of observations that can be made.
The population mean can be found using the following formula:
\[\large \mu=\frac{\sum X_i}{N}\]
Where,
\(\begin{array}{l}∑X_{i}\end{array} \)
 = Sum of the valuesN = Number of the value
Solved Example
Question:Â Find the population mean of the following numbers 1, 2, 3, 4, 5.
Solution:
Given,
\(\begin{array}{l}X_{i}\end{array} \)
 = 1, 2, 3, 4, 5\(\begin{array}{l}∑X_{i}\end{array} \)
 = 1 + 2 + 3 + 4 + 5 = 15N = 5
Population Mean = \(\begin{array}{l}\frac{\sum X_{i}}{N}\end{array} \)
\(\begin{array}{l}\mu\end{array} \)
 = \(\begin{array}{l}\frac{15}{5}\end{array} \)
\(\begin{array}{l}\mu=3\end{array} \)
Population Mean = 3
