#
There are 60 students in a class. The following is the frequency distribution of the marks obtained by the students in a test

Marks | 0 | 1 | 2 | 3 | 4 | 5 |

Frequency | x – 2 |
x |
x ^{2} |
(x + 1)^{2} |
2x |
x + 1 |

where,

*x*is a positive integer. Determine the mean and standard deviation of the marks.