Suppose we have a bag with 10 slips of paper in it. Eight slips have a 3 on them and the other two have a 9 on them.
How many 's do we have to add to make the expected value equal to 6?
+2666 I will assume the question is supposed to be a 9.
We can write as equation:
\(3 \times 8 + 9 \times 2 + 9x = 6(10+x)\)
\(42 + 9x = 60 + 6x\)
\(18 = 3x\)
\(x = \color{brown}\boxed{6}\)
