I have parameterized a shape in excel. It plots a smooth curve, and I am perfectly fine with the shape it gives. Now, I want to find out the way, the smooth curves are fit, for me to calculate the curve data at very small intervals.

I have the data of the curve, for which excel has plotted a smooth curve as follows,

x | y |

-0.25 | 0 |

1.53144E-17 | 0.25 |

2 | 0.75 |

5 | 1.5 |

15 | 0.45 |

20 | 0.15 |

20.15 | -1.83772E-17 |

I plot the above data using **scatter with smooth lines** option. Now, I want to find out the values of Y, for this curve that excel has fit, as a smooth line, for smaller intervals of X,

x

-0.25

-0.23

-0.2

-0.18

and so on..

I need to find what is the value of y, for this curve that excel has fit (**by scatter with smooth lines option**), for different intervals of X