Ihave to figure out the mean of 11+12+12+13+12 divided by 12 and what i have so far is: 23+25+12 divided by 48+12 divided by 60 divided by 12 and my answer was 24, but 24 times 12 equals 288 so could someone me out here?

Liz is shipping a package to her friend. the maximum weight of a medium flat-rate box is 20 pounds, including the box which weighs 6 ounces. write and solve an inequality to describe the possible weight in pounds, w, of the contents that liz will ship to her friend if she must use a medium flat-rate box. use the drop-down menus to explain your answer.