SAS EG Sum(Case When...) Error - sas

Question

I have been working on a two step process in SAS EG that creates a temporary table (connected to Netezza) then uses that table to build the final summary table. When creating the final table, I am trying to have two calculated columns that represent averages of all sales quotes and only customers that accepted the quote (i.e. the expectation is that the customers who accept have a lower average quote than all inquiries combined). In order to segment customers that accepted the quoted offer versus those that did not, I have attempted to use Sum(Case When...) and Sum with a Boolean operator.
I have the following code with the final three sum statements trying to create the same column in different ways (just looking for one that works). The first two attempts return an error saying that it was unable to identify a function that satisfies the given argument types. The final attempt (which is where I began things) does not recognize the syntax, which I feel is correct. The error occurs after the closed parentheses around "END." Any help would be greatly appreciated:
EXECUTE (
CREATE TABLE SAMPLE1 AS
SELECT DATE
,STATE
,SUM(INQRY_CN) AS INQ_COUNT
,(SUM(BOUND_IN)/INQ_COUNT) AS CLOSURE
,SUM(QUOTE_AMOUNT) AS AVG_QTD_AM
**,SUM(QUOTE_AMOUNT*(DAY_OF_QUOTE <> '01JAN1901')) AS AVG_BND_AM
,SUM(QUOTE_AMOUNT*(BOUND_IN=1)) AS AVG_BND_AM
,SUM(CASE WHEN BOUND_IN=1 THEN QUOTE_AMOUNT
ELSE . END) AS AVG_BND_AM**
FROM TEMP_TABLE
GROUP BY 1,2
ORDER BY 1,2
) BY NETEZZA;
DISCONNECT FROM NETEZZA;
QUIT;