In a company having 120 employees, 60 earn $500 per month, 40 earn $600 per month, and 20 earn $1000 per month. determine the mean earnings per month.

In order to determine the mean earnings per month, you need to calculate the sum of the earnings of all the employees then divide it by the number of employees. To compute the total earnings of all the employees, you have to multiply the specific earnings of a certain group of employees with their specific earnings.

Number of employees     x         Earnings per month             =         Total

         60                                          $500                                     $30,000

         40                                          $600                                     $24,000

         20                                          $1,000                                  $20,000

Total earnings                                                                              $74,000

Mean = $74,000/120

          = $616.67

none of the above.

for one of the equations to be used in the process, there has to be a term in the equation since squared is .

since there is only a term in the first equation, we cannot derive a from completing the square.

solving with completing the square