Google-sheets – How to copy over a value from another worksheet depending on the adjacent column

The solution, as I understand it, is as follows.

By setting a FILTER formula (array & condition) you create the first step, the "what are we looking for, specifically" then that formula gets wrapped in a SUM formula which adds the array values.

So, in the case above =SUM(FILTER(B:B,A:A="June")) this formula is looking for the values, all of them, in column B and then it filters the results if those values meet the criteria, in my case anything with June. Lastly, it adds those values. Here you can see the updated sheet with the formula in action.

Since the content of L7 is going to be overwritten, spreadsheet formulas cannot perform such reset. You need a script that has the spreadsheet keys of all the spreadsheets to be changed, and has the authority to edit them (i.e., the Google account under which it runs has this authority). It can be either a stand-alone script, or bound to your master spreadsheet, whichever is more convenient. Also, you'll need to know the name of the sheet within the spreadsheet in which the cell L7 is located; apparently it's "FailingStudents".

function reset() {
  var keys = ['....', '....' ]; // list of spreadsheet ids
  for (var i = 0; i < keys.length; i++) {
    var ss = SpreadsheetApp.openById(keys[i]);
    var sheet = ss.getSheetByName('FailingStudents');
    sheet.getRange('L7').setValue('No');
  }
}

Once you run this, the cell FailingStudents!L7 will be set to No in all listed spreadsheets.