linest()

3rd order polynomial fitting coefficients, e.g.

y = a0 + a1*x + a2*x^2 + a3*x^3

a0 = INDEX(LINEST(D2:D8,$A$2:$C$8,1,1),1,4)

a1 = INDEX(LINEST(D2:D8,$A$2:$C$8,1,1),1,3)

a2 = INDEX(LINEST(D2:D8,$A$2:$C$8,1,1),1,2)

a3 = INDEX(LINEST(D2:D8,$A$2:$C$8,1,1),1)

Chose a box range on the table

type LINEST(D2:D8,$A$2:$C$8,1,1) in the function input blank bar

Ctrl+Shift+Enter

the output is

a3 a2 a1 a0

se3 se2 se1 se0 (standard error)

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