Question 107575
I'm assuming this is a linear relation with a negative slope.
I want the vertical axis to be p = percent of present forest
remaining
The horizontal axis is years from the present
The points given are
P1 = (20,.53)
P2 = (x,.05) note that 95% removed leaves 5% left
Also I have the p-intercept (0,1) where 0  represents the present
The equation is {{{p = mx + 1}}} note that when x=0, p = 1 
The slope is {{{(p[2] - p[1]) / (x[2] - x[1])}}}
{{{ m = (.53 - 1) /(20 - 0)}}}
{{{m = -.47 / 20}}}
{{{m = -.0235}}}
{{{p = -.0235x + 1}}}
The question is, when p = .05, what is x?
{{{.05 = -.0235x + 1}}}
{{{-.0235x = -.95}}}
{{{x = 40.43}}}years answerThis is about 40 y 5 m 5 d