question type:equation because i set relevance of Q1,Q2,Q3,Q4.this equation question value should be :
if user relevant questions is Q1,Q2,Q4,should be of (Q1+Q2+Q4)/3.
if user relevant questions is Q1,Q3,should be of (Q1+Q4)/2.
BUT IN RESPONSE TABLE, THE VALUE IS 0.

what's the problem?

Q1.NAOK : .NAOK - same as .code, but can be part of calculations or lists even if irrelevant .

Else give error

i use Q1.valueNAOK,even Q1 is irrelevant, the Q1.valueNAOK is 0
it means no there's no error in Q1.valueNAOK.
and i check the response, Q1 is answered, the problem is {round((Q1.valueNAOK+Q2.valueNAOK+Q3.valueNAOK+Q4.valueNAOK)/count(Q1,Q2,Q3,Q4),2)} is 0.

BUT count(Q1,Q2,Q3,Q4) does error.

If you trye with (Q1.NAOK,Q2.NAOK,Q3.NAOK,Q4.NAOK) ?

as to count, q1 equal to q1.NAOK
i recreat the survey, this problem disappear.
i think the problem is about
Error executing query in dbExecuteAssoc:CDbCommand failed to execute the SQL statement: SQLSTATE[42S22]: Column not found: 1054 Unknown column
but i have no idea what cause this problem.