Al is a medical doctor who conducts his practice as a sole proprietor. During 2021, he received cash of $379,800 for medical services. Of the amount collected, $31,200 was for services provided in 2020. At the end of 2021, Al had accounts receivable of $98,200, all for services rendered in 2021. In addition, at the end of the year, Al received $12,000 as an advance payment from a health maintenance organization (HMO) for services to be rendered in 2022.

a. Compute Al's gross income for 2021 using the cash basis of accounting. $_______

b. Compute Al's gross income for 2021 using the accrual basis of accounting. $_____