If a company has 5 employees with annual salaries of $20,000, $40,000, $20,000, $60,000, and $70,000, respectively, what is the mean annual salary at the company?

20,000+40,000+20,000+60,000+70,000=210000
210000/5=42000

Mean is where you add all of the values together and then divide the total by the number of values. After doing this you should see this...
20,000+40,000+20,000+60,000+70,000 = 210,000 After you get this number you divide by the number of values, in this case, 5. 210,000/5 = 42,000