I have data like below,
| Item | month | sales |
| chair | 202401 | 100 |
| chair | 202402 | 200 |
| chair | 202403 | 300 |
| table | 202401 | 200 |
| table | 202402 | 300 |
| table | 202403 | 400 |
| mouse | 202401 | 300 |
| mouse | 202402 | 400 |
| mouse | 202403 | 500 |
I need the below output,
| Item | month | sales | Avg sales | Calculation Logic |
| chair | 202401 | 100 | 100 | Avg of sales (202401) |
| chair | 202402 | 200 | 150 | avg of sales (202401 & 202402) |
| chair | 202403 | 300 | 200 | avg of sales (202401 & 202402 & 202403) |
| table | 202401 | 200 | 200 | Avg of sales (202401) |
| table | 202402 | 300 | 250 | avg of sales (202401 & 202402) |
| table | 202403 | 400 | 300 | avg of sales (202401 & 202402 & 202403) |
| mouse | 202401 | 300 | 300 | Avg of sales (202401) |
| mouse | 202402 | 400 | 350 | avg of sales (202401 & 202402) |
| mouse | 202403 | 500 | 400 | avg of sales (202401 & 202402 & 202403) |
Help me achieving this in alteryx.