I have a DataFrame which I want to extend based on moving Average. So for example:
Week Number    |     Cumulative Sum
1                     24
2                     52
3                     74
Now what I want to do is to extend the data for next 3 weeks like this:
Week Number    |     Cumulative Sum
1                     24
2                     52
3                     74
4                     (24+52+74)/3 = 100.667
5                     (100.667+52+74)/3 = 75.556
6                     (75.556+100.667+74)/3 = 83.407
Can someone help me understanding how I can extend this?
 
    