Solution to Excel BI Excel/Power Query Challenge 19

gistfile1.txt

let
  Source = #"Sentences Raw",
  AddedIndex = Table.AddIndexColumn(Source, "Index", 1, 1, Int64.Type),
  SplitBySpaces = Table.ExpandListColumn(Table.TransformColumns(AddedIndex, {{"Sentence", Splitter.SplitTextByDelimiter(" ", QuoteStyle.Csv), let itemType = (type nullable text) meta [Serialized.Text = true] in type {itemType}}}), "Sentence"),
  TrimmedText = Table.TransformColumns(SplitBySpaces,{{"Sentence", Text.Trim, type text}}),
  WordLength = Table.AddColumn(TrimmedText, "WordLength", each Text.Length( [Sentence] )),
  MaxLengthBySentence = Table.Group(WordLength, {"Index"}, {{"AllData", each _, type table [Sentence=text, Index=number, WordLength=number]}, {"MaxLength", each List.Max([WordLength]), type number}}),
  ExpandedAllData = Table.ExpandTableColumn(MaxLengthBySentence, "AllData", {"Sentence", "WordLength"}, {"Sentence", "WordLength"}),
  AddedLengthEqMaxLen = Table.AddColumn(ExpandedAllData, "LengthEqMaxLen", each if [WordLength] = [MaxLength] then 1 else 0),
  FilteredToMaxLenWords = Table.RemoveColumns( Table.SelectRows(AddedLengthEqMaxLen, each ([LengthEqMaxLen] = 1)), {"WordLength", "MaxLength", "LengthEqMaxLen"}),
  CapitalizedWords = Table.TransformColumns(FilteredToMaxLenWords,{{"Sentence", Text.Proper, type text}}),
  GroupedRows = Table.Group(CapitalizedWords, {"Index"}, {{"AllData", each _, type table [Index=number, Sentence=text]}}),
  #"Extracted&Cleanup" = Table.RemoveColumns( Table.AddColumn(GroupedRows, "Expected Answer", each Text.Combine( [AllData][Sentence], ", ")), {"Index", "AllData"})
in
  #"Extracted&Cleanup"