Class 10

Math

All topics

Statistics

To find out the concentration of $SO_{2}$ in the air (in parts per million, i.e., ppm), the data was collected for $30$ localities in a certain city and is presented below:

Concentration of $SO_{2}$ (in ppm) | Frequency |

$0.00−0.04$ | $4$ |

$0.04−0.08$ | $9$ |

$0.08−0.12$ | $9$ |

$0.12−0.16$ | $2$ |

$0.16−0.20$ | $4$ |

$0.20−0.24$ | $2$ |

Calculating mean, we get

Mean, $xˉ=n1 ∑f_{i}x_{i}$

Here, $n=30,∑f_{i}x_{i}=2.96$

Therefore, Mean, $xˉ=302.96 =0.099$ ppm

We have used direct method because numerical values of $f$ and $x$ are small.