Calculate CPP from following employess: 

1- Sara regular earnings are $ 4678 and her pay period is Monthly. 

2- John turned 18 on July 12. Calculate his total CPP contribution for the year 

3- Melissa died on May 19. Calculate her maximum contributions for the year. 

4- Sabeen is a commissioned employee and she receives her pay only when she makes sale. She received $5650 this month. There are 38 days between this and last payment. Calculate CPP from the commission payment.