Final answer:
The unweighted mean, also known as the average or arithmetic mean, is the sum of all values divided by the number of values, giving equal weight to all data points. It is different from the weighted mean, which factors in the relative importance or frequency of the values.
Step-by-step explanation:
The unweighted mean, also known as the arithmetic mean or average, is a measure of central tendency that gives equal weight to all values in the data set. This type of mean is calculated by adding up all the values and dividing by the number of values. For example, if a data set consists of the values 2, 3, and 5, the unweighted mean would be calculated as (2+3+5)/3, which equals 3.33. It does not take into account other factors such as the relative importance of each value.
On the other hand, the weighted mean is used when some values are considered more important than others. In this case, each number is multiplied by a weight before the sum is divided by the sum of the weights. This method is often used when dealing with data that contain frequencies or when uneven emphasis is required.
The average in common language may refer to any central tendency measure; however, in statistics, it often implies the unweighted mean. It's important not to confuse the terms in contexts where precision is required.