To find the mean (average) of a data set, follow these steps:

1. Gather all the numbers in the data set.
2. Count how many numbers there are; this count is called nnn.
3. Add all the numbers together to get a total sum.
4. Divide the sum by nnn (the number of values).

The formula for the mean xˉ\bar{x}xˉ is:

xˉ=sum of all data valuesn\bar{x}=\frac{\text{sum of all data values}}{n}xˉ=nsum of all data values​

For example, if the data set is 70, 65, 75, 60, 55, 59, 68, 74, 50:

• Sum: 70+65+75+60+55+59+68+74+50=57670+65+75+60+55+59+68+74+50=57670+65+75+60+55+59+68+74+50=576
• Count: n=9n=9n=9
• Mean: 576/9=64576/9=64576/9=64

So, the mean is 64, which represents the average value of the data set.