Which statements about characteristics of the Aztec's civilization are true? Choose all answers that are correct.
settled in the Valley of Mexico around the year 1250
built a high mountain city, probably as a retreat for nobility
stone masons fitted gigantic blocks of stone without using mortar
found a permanent home on an island where an eagle tore apart a serpent

it affected it because the kingdoms (with trade) slowly got richer and richer.

the correct answer is:   "   3.6 % " .

          →   the unemployment rate is:   " 3.6 % " .

explanation:

to calculate the "unemployment rate" :

the "unemployment rate"   =

  [# of people unemployed] /   [working age population]   * 100 %   ;

                =   [9 million] / [250 million]     *   100 % ;

    →     note:   the units of "million" cancel out;

                    since:   " {million} / {million} = 1 " ;

                =   (9 / 250)   * 100 %   ;

                = 0.036 * 100 % ;

                =   3.6 %

answer:   the unemployment rate is:   " 3.6 % " .