statistics
posted by meena .
in a batch of 15 students failed in a test. the marks of 10 who have passed were 9,6,7,8,8,9,6,5,4,7.find the median of all 15 students.

It would help if you proofread your questions before you posted them. With 10 scores listed, I assume 5 failed.
The five who have failed must have scores below the lowest passing score. Arrange in order of value.
x,x,x,x,x,4,5,6,6,7,7,8,8,9,9.
If you are not evaluating within the interval, the median = 6