What does the mean represent in a set of numbers

Look at the figure below: triangle abc is a right triangle with angle abc equal to 90 degrees. the length of ac is 5 units and the length of ab is 4 units. d is a point above c. triangle adc is a right triangle with angle dac equal to 90 degrees and dc parallel to ab. what is the length, in units, of segment cd?

Write 37/22 as a decimal rounded to the nearest hundredth.

Arectangular courtyard is 12 feet long and 8 feet wide. a tile is 2 feet long and 2 feet wide. how many tiles are needed to cover the courtyard?