If the mean of the following distribution is 50, and the sum of all the frequencies is 40, then estimatethe value of the frequencies \(a\) and \(b\).
| Class interval | \(20 - 30\) | \(30 - 40\) | \(40 - 50\) | \(50 - 60\) | \(60 - 70\) | \(70 - 80\) |
| Frequency | 6 | \(a\) | 6 | 5 | \(b\) | 2 |
The value of the frequency \(a\) is .
The value of the frequency \(b\) is .