replace nulls with last 3 months average

[MMB920]

Hello Community,

Am looking for a power query that would help me replace the null values highlighted to the last 3 months average i.e.(July to Dec 2023 = (June,May,Apr)/3

Would greatly appreciate your input to resolve.. thank you.

MMB

[m_dekorte]

Hi @MMB920,

Give this a go.

let
    Last3Months = Number.Round( List.Average( List.ReplaceMatchingItems( 
        Table.SelectRows( Source, each Date.IsInPreviousNMonths([month_], 2) or Date.IsInCurrentMonth([month_]) )[ib_call_pct], 
        {{null, 0}} )), 4 
    ),
    Source = Table.FromColumns(
        {
            List.Transform( {1..12}, each #date( 2023, _, 1) ),
            {.1655, null, .1442, .1506, .162, .0196, null, null, null, null, null, null}
        }, type table[ month_ = date, ib_call_pct = Percentage.Type]
    ),
    Replaced = Table.ReplaceValue( Source, each Record.ToList(_), each Record.ToList(_), (x, y, z)=> if (y{0} > Date.From( DateTime.FixedLocalNow()) and y{1} = null) then Last3Months else x, {"ib_call_pct"} )
in
    Replaced

with this result

Ps. If this helps you solve your query, please mark it as solution. Thanks!