multiply and sum column on condition

I would like to get the sum of a column, but am having trouble with a condition

|  Target  |  MultiOnQry  |   
---------------------------
|  50393   |       1      |
|  49      |       1      |
|  303     |       0      |
|  1934    |       1      |
|  45      |       0      |
---------------------------

I want to sum the truncated values from the target column, but want to multiply by X if MultiOnQry = 1. This is being called from vba, so I will substitute X for the scalar.

SELECT SUM(CAST(Target*X AS Integer)) AS TargetSum FROM table WHERE ID = 1078