135 112.94 121.86 114.42 105.92 92.09 80.03 66.23 52.65 45.71 38.24 30.39 24.01 18.34 16.82 15.48 13.88 12.44

好的，给定数据如下：

135 112.94 121.86 114.42 105.92 92.09 80.03 66.23 52.65 45.71 38.24 30.39 24.01 18.34 16.82 15.48 13.88 12.44

现在我们来计算四项移动平均：

首先是一项移动平均，即n=1，每个数据点的移动平均值就是它本身。

接下来是二项移动平均，即n=2，每个数据点的移动平均值为相邻两个数据点的平均值：

(135+112.94)/2=123.97

(112.94+121.86)/2=117.40

(121.86+114.42)/2=118.14

(114.42+105.92)/2=110.17

(105.92+92.09)/2=99.01

(92.09+80.03)/2=86.06

(80.03+66.23)/2=73.13

(66.23+52.65)/2=59.44

(52.65+45.71)/2=49.18

(45.71+38.24)/2=41.98

(38.24+30.39)/2=34.31

(30.39+24.01)/2=27.20

(24.01+18.34)/2=21.18

(18.34+16.82)/2=17.58

(16.82+15.48)/2=16.15

(15.48+13.88)/2=14.68

(13.88+12.44)/2=13.16

接下来是三项移动平均，即n=3，每个数据点的移动平均值为相邻三个数据点的平均值：

(135+112.94+121.86)/3=123.60

(112.94+121.86+114.42)/3=116.07

(121.86+114.42+105.92)/3=114.07

(114.42+105.92+92.09)/3=104.81

(105.92+92.09+80.03)/3=92.68

(92.09+80.03+66.23)/3=79.78

(80.03+66.23+52.65)/3=66.97

(66.23+52.65+45.71)/3=54.53

(52.65+45.71+38.24)/3=45.87

(45.71+38.24+30.39)/3=38.11

(38.24+30.39+24.01)/3=30.55

(30.39+24.01+18.34)/3=24.25

(24.01+18.34+16.82)/3=19.39

(18.34+16.82+15.48)/3=16.55

(16.82+15.48+13.88)/3=15.06

(15.48+13.88+12.44)/3=13.60

最后是四项移动平均，即n=4，每个数据点的移动平均值为相邻四个数据点的平均值：

(135+112.94+121.86+114.42)/4=121.05

(112.94+121.86+114.42+105.92)/4=113.03

(121.86+114.42+105.92+92.09)/4=108.57

(114.42+105.92+92.09+80.03)/4=98.12

(105.92+92.09+80.03+66.23)/4=86.32

(92.09+80.03+66.23+52.65)/4=72.25

(80.03+66.23+52.65+45.71)/4=61.15

(66.23+52.65+45.71+38.24)/4=50.96

(52.65+45.71+38.24+30.39)/4=41.75

(45.71+38.24+30.39+24.01)/4=34.09

(38.24+30.39+24.01+18.34)/4=27.25

(30.39+24.01+18.34+16.82)/4=22.14

(24.01+18.34+16.82+15.48)/4=18.66

(18.34+16.82+15.48+13.88)/4=16.13

(16.82+15.48+13.88+12.44)/4=14.16

可以看出，随着时间窗口大小的增加，趋势平均值的变化更加缓慢，波动也更小。