Data management grade 12 math

Question

Twenty disks are marked and placed in a bag. The markings are as follows: $2 is marked on 8 disks. $4 is marked on 6 disks. $6 is marked on 4 disks. $10 is marked on 2 disks. A game consists of drawing one disk from the bag and you win the amount on the disk. The cost to play the game is $4, is the game fair?

Answer 1

There are twenty total discs. The average value of the twenty discs is

2 x (8/20) + 4 x (6/20) + 6 x (4/20) + 10 x (2/20) = $ 4.20 which is bigger than $ 4. Therefore, the game is fair.