- [Maximum mark: 6]
The marks obtained by students in a class quiz are shown in the following table where .

| Marks | Frequency |
|---|---|
| 20 | 12 |
| 35 | |
| 8 |
The mean and Variance of the marks are 31 and 124 respectively.
Find the value of and the value of .
The marks obtained by students in a class quiz are shown in the following table where .

| Marks | Frequency |
|---|---|
| 20 | 12 |
| 35 | |
| 8 |
The mean and Variance of the marks are 31 and 124 respectively.
Find the value of and the value of .