Why did the united states become involved in world war 1?

The U.s tried to remain neutral however, little things the opposing sides did began to change their stance. Britain propaganda, the sinking of ships by German U-boats, the final thing that pushed them over the edge was the "Zimmerman" note. A note that tried to get Mexico to declare war on the U.s.

i am sure the answer is d

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 % " .