=IF(AND(A1>=70,A1<75),35,IF(A1>=80,45,"不在范围内"))
=IF(AND(A1>=70,A1<75),25,IF(AND(A1>=75,A1<80),35,IF(A1>80,45,"")))
=IF(A1<70,"",IF(A1<75,25,IF(A1<80,35,45)))公式意思是:当A1小于70时,返回空白文本;当A1小于75时,返回25;当A1小于80时,返回35;否则(即不满足以上所有条件时,即A1>=80的情况),返回45。