Can someone explain the meaning of 'proxied by' in math? or What does 'proxied by' mean in mathematic

"Proxied by" is when you use a simpler or more available thing to estimate another.

Kinda like using your height to guess your shoe size—not exact, but often works.

In regression, you’ll see this a lot with proxy variables.

Try searching for "proxy variables in statistics" for deeper dives.