#### notes

The given discrete frequency distribution be

`x : x_1, x_2, x_3 ,. . . , x_n`

`f : f_1, f_2, f_3 ,. . . , f_n`

In this case standard deviation

(σ) = \[\sqrt{{\frac{1}{N}}\displaystyle\sum_{i=1}^{n} f_i (x_i - \bar{x} )^2} \]

where N = \[\displaystyle\sum_{i=1}^{n} f_i\].

#### Shaalaa.com | Standard Deviation Discrete series

#### Related QuestionsVIEW ALL [7]

Calculate the mean, variance and standard deviation of the following frequency distribution.

Class: | 1–10 | 10–20 | 20–30 | 30–40 | 40–50 | 50–60 |

Frequency: | 11 | 29 | 18 | 4 | 5 | 3 |

Find the mean and variance for the following frequency distribution.

Classes |
0-30 |
30-60 |
60-90 |
90-120 |
120-150 |
150-180 |
180-210 |

Frequencies |
2 |
3 |
5 |
10 |
3 |
5 |
2 |

Find the mean and variance for the following frequency distribution.

Classes |
0-10 |
10-20 |
20-30 |
30-40 |
40-50 |

Frequencies |
5 |
8 |
15 |
16 |
6 |