How do i find the growth factor

In stepmber, daniel and justin opened a business. during their first three months of business, their average monthly profit was $51. if during their first month, they lost $29, and during their second month, they gained $115, what was their profit or loss for their third plzzz i will give you 299 points

An expression for the average of x 2x and 3y

Can someone tell me if these are correct?