Class 10

Math

All topics

Statistics

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

Class | $0−10$ | $10−20$ | $20−30$ | $30−40$ | $40−50$ | $50−60$ |

Frequency | $7$ | $5$ | $6$ | $12$ | $8$ | $2$ |

Class interval | Frequency $f_{i}$ | Mid-Value $x_{i}$ | $f_{i}x_{i}$ |

$0−10$ | $7$ | $5$ | $35$ |

$10−20$ | $5$ | $15$ | $75$ |

$20−30$ | $6$ | $25$ | $150$ |

$30−40$ | $12$ | $35$ | $420$ |

$40−50$ | $8$ | $45$ | $360$ |

$50−60$ | $2$ | $55$ | $110$ |

$∑f_{i}=40$ | $1150$ |

Mean $=∑f_{i}∑f_{i}x_{i} $

$=401150 $

$=28.75$