If a company has 5 employees with annual saleries of $40,000, $50,000, $40,000, $60,000 and $90,000 what is the mean anulal salary at the company?

To find the mean of something, add all the numbers then divide by the number of numbers there are. 
40,000 + 50,000 + 40,000 + 60,000 + 90,000 = 280,000
Then divide:
280,000/5 = 56,000

The mean of the annual salaries at the company is 56,000

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