Statistics Problem

$$
N = \sum f = 8+4+2+2+20+17+10+15+20+22+22+15
$$
$$
N = 157
$$
$$
\boxed{\text{157 candidates}}
$$

$$
\text{Median position} = \frac{N+1}{2} = \frac{157+1}{2} = \frac{158}{2} = 79^{\text{th}}
$$

| Subjects (x) | Candidates (f) | Cumulative Frequency (cf) |
| :------------ | :-------------- | :------------------------ |
| 0             | 8               | 8                         |
| 1             | 4               | 12                        |
| 2             | 2               | 14                        |
| 3             | 2               | 16                        |
| 4             | 20              | 36                        |
| 5             | 17              | 53                        |
| 6             | 10              | 63                        |
| 7             | 15              | 78                        |
| 8             | 20              | 98                        |
| 9             | 22              | 120                       |
| 10            | 22              | 142                       |
| 11            | 15              | 157                       |
The $79^{\text{th}}$ value falls within the group of 8 subjects (since cf 78 is for 7 subjects, and cf 98 is for 8 subjects).
$$
\boxed{\text{8 subjects}}
$$

The highest frequency is 22, which occurs