Given the following table, compute the mean of the grouped data.
| Class | Midpoint | Frequency |
| \([9,15)\) | \(2\) | |
| \([15,21)\) | \(1\) | |
| \([21,27)\) | \(9\) | |
| \([27,33)\) | \(7\) | |
| \([33,39)\) | \(5\) | |
| \([39,45)\) | \(1\) | |
| \([45,51)\) | \(0\) | |
| Totals |
What is the mean of the grouped data?