Finding y-axis value

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    Hi and top of the day,

    I'm a newbie here, so please excuse my kinda silly question.

    Anyway, i have a problem with excel formula. Attached is the example of the data that i have in excel.

    I have the MW and MC values from which i can make a graph that looks like this.


    So what i want to do next is, i want to find the value of pi1, pi2, pi3, and pi4 (which is the y-axis value) by refferring to the value of component 1, component 2, component 3, and component 4 respectively.

    I tried using LOOKUP function, but i'm not happy with the given value as it gives the nearest value instead of the exact one.

    Can anyone please help me? I really need some help on this. Thanks in advance :)