A company has three establishments A,B and C in three cities. Analysis of the daily wages paid to the employees in the three establishments is given below:
| Establishments: | A | B | C |
| Number of employees: | 20 | 25 | 40 |
| Average daily wages: | 305 | 300 | 340 |
| Standard Deviation: | 50 | 40 | 45 |
Find the average and standard deviation of the wages of all the 85 employees in the company.
1 Answer