Question 766504
You are saying, apparantly, the included point is the vertical axis intercept at (0, 0.41)  or is it (0, 4.1)?  


{{{y=ab^x}}} and taking natural log both sides gives a linear equation:
{{{ln(y)=x*ln(b)+ln(a)}}}______ a linear equation, vertical intercept ln(a) and slope ln(b).


Finding b is not a problem.  Finding a, maybe a little problem, depending on vertical intercept.

{{{1.8=ln(b)}}} so {{{highlight(b=6.05)}}}


The vertical intercept is for x=0, so you have this:
{{{ln(y)=0*(1.8)+ln(a)}}}
Either {{{ln(a)=ln(0.41)}}} Or {{{ln(a)=ln(4.1)}}} depending on which you really have.  Find a from the proper one.


If vertical intercept 0.41, then {{{a=1.51}}}
......OR
If vertical intercept 4.1, then {{{a=60.3}}}