There's no way to find the mass with the information given.
"200 ft" and "875 ft" are linear dimensions ... things you would
measure with a ruler. They tell us how long or wide or high the
TV is. None of that information tells us anything about its mass.
By the way ... those are gigantic measurements. I was working
in Wrigley Field here in Chicago just before opening day in 2015,
when the new video screens were being installed. I saw them
up close while the cranes lifted them into position. None of the
Chicago Cubs' new screens is as big as the numbers in the question,
and I'm pretty sure the whole score-board isn't that big either.
Something is definitely wrong here.