# Find the mean and variance for the data 6, 7, 10, 12, 13, 4, 8, 12

**Solution:**

The given data is 6, 7, 10, 12, 13, 4, 8, 12.

Mean of the data is given by

x = (∑^{8}_{i = 1}x_{i})/n

= (6 + 7 + 10 + 12 + 13 + 4 + 8 + 12)/8

= 72/8

= 9

The following table is obtained from the given above data

x_{i} |
(x_{i} - x) |
(x_{i} - x)^{2} |

6 | -3 | 9 |

7 | -2 | 4 |

10 | 1 | 1 |

12 | 3 | 9 |

13 | 4 | 16 |

4 | -5 | 25 |

8 | -1 | 1 |

12 | 3 | 9 |

74 |

Variance of the data

(σ²) = 1/n ^{8}∑_{i = 1}(x_{i} - x)^{2}

= 1/8 × 74

= 9.25

NCERT Solutions Class 11 Maths Chapter 15 Exercise 15.2 Question 1

## Find the mean and variance for the data 6, 7, 10, 12, 13, 4, 8, 12

**Summary:**

The mean and variance for the given data are 9 and 9.25