If $n$ And $k$ Are Positive Integers And $2 ^ { k } \leq n < 2 ^ { k + 1 }$

Essay

If $n$ and $k$ are positive integers and $2 ^ { k } \leq n < 2 ^ { k + 1 }$ , what is $\left\lfloor \log _ { 2 } ( n ) \right\rfloor$ ? Be sure to justify each step of your answer.