incorrect results in percentile functions

[axxName]

CREATE TABLE test (num INT);

insert into test values(1); insert into test values(2); insert into test values(3); insert into test values(4); insert into test values(9);

select percentile_75(num) from test; sqlite> select percentile_75(num) from test; 4.0

But values in table are INTegers, not float!

[nalgeon]

The return type of the precentile function is real, regardless of its argument type.