In Excel - can I create a formula based on a filter?
 

I'm using Excel to create a report based on survey results. For example, for
the % of users who got a first response in less than a day, I have this:

=(COUNTIF(SurveyReport!D2:D28,"less than a
day"))/((COUNTIF(SurveyReport!D2:D28,"less than a
day"))+(COUNTIF(SurveyReport!D2:D28,"1 - 2
days"))+(COUNTIF(SurveyReport!D2:D28,"3 - 7
days"))+(COUNTIF(SurveyReport!D2:D28,"longer than a week")))

Right now, I have to manually sort the data and enter the ranges each time I
run the report, since the number of respondents changes each time. If the
responses are in column D, and the question ID is in column A, is there a way
to tell Excel "do this for every row where A=3"?