80,82,79,69,74,78,x,81这组平均数是77则x是多少

问题描述:

80,82,79,69,74,78,x,81这组平均数是77则x是多少

77x8-80-82-79-69-74-78-81

(80+82+79+69+74+78+x+81)=77×8
x=73