On December 1, Karl Zant opened a speech and hearing clinic. During December, his firm had the following transactions involving revenue and expenses. Did the firm earn a net income or incur a net loss for the period? What was the amount?

Paid $6,200 for advertising.
Provided services for $20,800 in cash.
Paid $1,920 for telephone service.
Paid salaries of $5,200 to employees.
Provided services for $6,000 on credit.
Paid $1,800 for office cleaning service.