=AVERAGE(IF(AND(F3:F16>=0,F3:F16<=30),F3:F16))或=AVERAGE(IF((F3:F16>=0)*(F3:F16<=30),F3:F16))按三键CTRL+SHIFT+ENTER结束公式输入
=SUMIF(A:A,"<30")/COUNTIF(A:A,"<30")A:A表示数据所在的列
