Class 11

Math

JEE Main Questions

Statistics

Find the mean and variance for each of the data :

Compute the mean of the following data, using direct method:

Class | $0−100$ | $100−200$ | $200−300$ | $300−400$ | $400−500$ |

Frequency | $6$ | $9$ | $15$ | $12$ | $8$ |

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 |

$0.00−0.04$ | $4$ |

$0.04−0.08$ | $9$ |

$0.08−0.12$ | $9$ |

$0.12−0.16$ | $2$ |

$0.16−0.20$ | $4$ |

$0.20−0.24$ | $2$ |