Boyd Salzer, an unmarried individual, has $212,950 AGI consisting of the following items.

Salary ........................................................................ $188,000
Interest income .......................................................       2,900
Dividend income .....................................................       8,300
Rental income from real property ........................     13,750

a. Compute Mr. Salzer’s Medicare contribution tax.

b. How would the computation change if Boyd Salzer files a joint income tax return with his wife Harriet?

Assume the taxable year is 2018.