如何理解SUM和IF函数组合
1、AND(I3:I17>=70,I3:I17<80)单元格满足条件与否

2、IF(AND(I3:I17>=70,I3:I17<80),1/I3:I17,0)满足条件

4、I3:I17*IF(AND(I3:I17>=70,I3:I17<80),1/I3:I17,0)满足条件相乘为1

6、最终函数为sum(I3:I17*1/I3:I17)或者sum(I3:I17*0),即结果为1或者0

1、AND(I3:I17>=70,I3:I17<80)单元格满足条件与否
2、IF(AND(I3:I17>=70,I3:I17<80),1/I3:I17,0)满足条件
4、I3:I17*IF(AND(I3:I17>=70,I3:I17<80),1/I3:I17,0)满足条件相乘为1
6、最终函数为sum(I3:I17*1/I3:I17)或者sum(I3:I17*0),即结果为1或者0