# Line of Best Fit(Eyeball Method)

A line of best fit is a straight line drawn through the maximum number of points on a scatter plot balancing about an equal number of points above and below the line.

It is used to study the nature of relation between two variables.

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The line of best fit in the scatter plot above rises from left to right; so, the variables have a positive correlation .

Here, the line of best fit drops from left to right, so the variables have a negative correlation.

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Example 1:
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Draw a line of best fit for the scatter plot given.

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Solution:
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Draw a line through the maximum number of points, balancing about an equal number of points above and below the line.

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Example 2:
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Draw a line of best fit for the scatter plot given.

Age of a Person (in years) ( $x$ ) | Annual Income (in $)( $y$ ) |

$32$ | $75000$ |

$40$ | $110000$ |

$35$ | $90000$ |

$36$ | $50000$ |

$37$ | $45000$ |

$39$ | $60000$ |

$34$ | $51000$ |

$39$ | $60000$ |

$41$ | $40000$ |

$45$ | $100000$ |

$47$ | $65000$ |

$49$ | $68000$ |

$53$ | $105000$ |

$55$ | $85000$ |

$43$ | $80000$ |

$44$ | $55000$ |

$50$ | $85000$ |

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Solution:
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Plot the age in the $x$ -axis and the income in the $y$ -axis and mark the points.

Draw a line through the maximum number of points balancing about an equal number of points above and below the line.