I have 4-week moving average trend line calculation using RangeAvg(Above(Sum(value),0,4)). Which will show correct values that we expected. While zooming the particular portion from the chart, then the trend-line showing wrong result. How to solve the problem. Or any other effective way is there to calculate the 4-week moving average calculation.
The above function you use cannot use values that are not shown in the chart. If you make a selection then then first weeks of the selection will show wrong results. There are solutions for that. See this document: Calculating rolling n-period totals, averages or other aggregations