HARMEAN
function HARMEAN(args: ApiRange | number[] = null): numberDescription
Returns the harmonic mean of a data set of positive numbers: the reciprocal of the arithmetic mean of reciprocals.
Parameters
Up to 255 numeric values for which the harmonic mean will be calculated.
Returns
numberTry It
var oWorksheet = Api.GetActiveSheet();
var oFunction = Api.GetWorksheetFunction();
var ans = oFunction.HARMEAN(28, 16, 878, 800, 1650, 2000);
oWorksheet.GetRange("B2").SetValue(ans);