12,20,16,18,20,28,23,16,15,18,20,24,18,21,18,19,18,31,18,13,
求这组数据的平均数,中位数,众数.
按照从小到大的顺序排列为:12,13,15,16,18,18,18,18,18,18,19,20,20,20,21,23,24,28,31,
中位数是(18+18)÷2=18,众数为18
小科家浴室内有台储水式电热水器,其说明书部分参数如下表。请回答下列问题: