Summary: Finding Averages and Basic Probabilities
Key Concepts
- Calculate the mean of a set of numbers.
- Write the formula for the mean [latex]\text{mean}=\frac{\text{sum of values in data set}}{n}[/latex]
- Find the sum of all the values in the set. Write the sum in the numerator.
- Count the number, n, of values in the set. Write this number in the denominator.
- Simplify the fraction.
- Check to see that the mean is reasonable. It should be greater than the least number and less than the greatest number in the set.
- Find the median of a set of numbers.
- List the numbers from least to greatest.
- Count how many numbers are in the set. Call this [latex]n[/latex] .
- Is [latex]n[/latex] odd or even?If [latex]n[/latex] is an odd number, the median is the middle value.If [latex]n[/latex] is an even number, the median is the mean of the two middle values
- Identify the mode of a set of numbers.
- List the data values in numerical order.
- Count the number of times each value appears.
- The mode is the value with the highest frequency.
Glossary
- mean
- The mean of a set of [latex]n[/latex] numbers is the arithmetic average of the numbers. The formula is [latex]\text{mean}=\frac{\text{sum of values in data set}}{n}[/latex]
- median
- The median of a set of data values is the middle value.
- Half the data values are less than or equal to the median.
- Half the data values are greater than or equal to the median.
- mode
- The mode of a set of numbers is the number with the highest frequency.
Licenses & Attributions
CC licensed content, Specific attribution
- Prealgebra. Provided by: OpenStax License: CC BY: Attribution. License terms: Download for free at http://cnx.org/contents/[email protected].