I'm being introduced to conversions this week in my hydrology course after having been away from math for quite some time (lol). So if these questions seem like a joke (too easy) then at least you know...

What is the sum of the following measurements? 35.0 ft, 1.35 ft, 72 in., 48.69 ft expressed a) in ft b) expressed in m.

I need to convert 72 in to ft to get similar units, so my total is 91.04 feet.

So I have a rule telling me that the absolute precision of a sum equals the absolute precision of the least absolutely precise number involved (would I keep my final answer as 91.04 ft then?)

Conversions are confusing me going from one unit to another, and my book only gives one example of miles to meters, showing the work. If anyone could show work on part b it would help me out (I realize there are many websites that will do conversions for you but they don't show how the answer was arrived at)