Question 1197150


let the fourth number be {{{x}}}

if the average of four numbers is {{{67}}}, and if three of these numbers are {{{56}}}, {{{87}}}, and {{{72}}}, we have

{{{(x+56+87+72)/4=67}}}

{{{(x+215)=67*4}}}

{{{x+215=268}}}

{{{x=268-215}}}

{{{x=53}}}


answer: the fourth number is {{{53}}}