Question 323967
Same as you would for a line, although the symbols are different,
{{{y=bx+a}}}
.
.
.
{{{b=SSXY/SSXX}}}
{{{a=yave-b*xave}}}
where {{{xave}}} and {{{yave}}} are the means of the input data, {{{SSXX}}} are the sum of the squares of the x deviations, {{{SSXY}}} are the products of the x and y square deviation terms.