A weighted average is an average that takes into account the relative importance or weight of each value in a data set. A simple average, also known as the arithmetic mean, is an average that treats all values in the data set as having equal importance.

Here is an example to illustrate the difference between the two. Let's say you have a data set with the following values: 2, 4, 6, and 8. The simple average of this data set would be (2+4+6+8)/4 = 5. The weighted average, on the other hand, would be calculated by multiplying each value by its corresponding weight and then dividing by the sum of the weights. For example, if the weights were 0.5, 1, 1.5, and 2, the weighted average would be (20.5+41+61.5+82)/(0.5+1+1.5+2) = 6.

As you can see, the weighted average takes into account the relative importance of each value in the data set, while the simple average does not. In this case, the weighted average is higher than the simple average because the higher values in the data set have more weight.