For example:
Average value: (9-3-11+20-5+6+1+3) ÷ 8+96.
Calculation:
1.5
2. 10
3.- 1 1
16 The number less than -5 is-21; A number greater than -8 times 4 is -4.
The sum of two numbers is-18.9, where one number is -9.5 and the other number is -9.4.
Special description of average value
1, the weighted arithmetic mean is affected by two factors at the same time, one is the size of each group, and the other is the distribution frequency of each group. Under the condition of constant value, the more frequency a group appears, the greater the effect of the group's value on the average value, and vice versa.
Frequency plays an important role in weighted arithmetic average, which is also the significance of weighted arithmetic average.
2. Arithmetic average is easily influenced by extreme value. For example, there are the following data: 5, 7, 5, 4, 6, 7, 8, 5, 4, 7, 8, 6, 20. The average value of all data is 7. 1. In fact, most data (including 10) are less than 7. If 20 is removed, the remaining 10.
It can be seen that the appearance of extreme value will interfere with the authenticity of the average value.