Error on summing up an indexed-repeat equation

Question

I'm new at creating equations in xls format and I'm struggle with getting this equation to function for a survey in survey 123.

I get this error in survey 123 : "TypeError: Value is undefined and could not be converted to an object in expression: sum(indexed-repeat( /Form_1/bio/biological_control_agent/bioamt , /Form_1/bio , position (..)))"

The equation is: sum(indexed-repeat(${bioamt}, ${bio}, position (..)))

The table below is a copy from the form I'm working with (maybe I don't' have the layout correct?)

Any help or insight would be greatly appreciated.

dougbrowning · Accepted Answer

indexed repeat returns just one value so cannot sum it.  If you just want to sum the values of the repeat simply

sum(${bioamt})

is enough