Gradebook

I have the following situation: There is a course whose grade is determined by a block of tasks and a test. The grade is calculated as a mean between those two. So far, so good.

The problem is, that it is neccesary, in order to pass the course, that the test is positive (>60% in my case) by itself. I am unable to tell moodle that because if a student fails the test slightly but was good enough on the second block, the averaged grade calculated would be positive and the student is shown a positive grade for the course.

Is it somehow possible, to make this happen in the gradebook?