Please help!!!

Lily Morrissette is studying an invasive species of mussels found in Lake Erie. She counts the number of mussels at her study site and finds 10. She returns 3 months later to find that the number of mussels has increased to 22. Lily wants to predict the population of mussels one year from when she started collecting data.

If Lily assumes the population grows at the same percentage rate each month, what would she predict the population of mussels to be in a year?

Write an equation to support your answer.

By the way, the equation is supposed to be in y=mx+b format