Here you go:
Try this :
timing - oops, I was modifying the format of your first formula, but this one works.
=($C$6*$B17)+($C$7*$C17)+($C$8*$D17)+($C$9*$E17)
Then next two students should be 94.2 and 54.2 - (i went a little blind copying the scores)
This formula can now be copied straight down the column.
The only thing that's "floating" is the row number.
And the student ID changes on each row.