ArcMap line symbol with two different ends

Question

Is it possible to create a line symbol that has a round line end at the one end and a straight line end at the other using ArcMap?

I am only able to do something like this with arrow line symbols:

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Answer 1

Use a "butt" style of line cap. This creates a flat end that stops exactly at the end of the line (as compared to "square" which extends the symbol past the geographic end of the line).

Add a marker symbol layer. Make the marker symbol a single black circle, the same width as the line, placed at the endpoint of the line.

Note: apparently this method works in ArcGIS Pro but not in ArcMap.