JAMB Mathematics 1982 Question 42

Determine the mean monthly salary of 50 employees of a company from the following frequency distribution:
Monthly salary: ₦200.00, ₦325.00, ₦100.00, ₦120.00, ₦60.00, ₦80.00
Frequency: 10, 5, 20, 2, 10, 3

1. A.₦215.30
2. B.₦134.10
3. C.₦143.10
4. D.₦80.00
5. E.₦50.30.