Posted by Soroban on September 02, 2002 at 19:32:18:
In Reply to: Equation posted by Joyce on September 02, 2002 at 11:34:46:
: R(w)=39.4 (1.998^w);R(w)=78.8, R(w)=394
You have to solve for w. (This will take a while.)
Switch sides: 39.4(1.998^w) = R
Then: 1.998^w = R/39.4
Take logs of both sides: log(1.998^w) = log(R/39.4)
From a Log Property: w*log(1.998) = log(R/39.4)
And finally: w = log(R/39.4) / log(1.998)
Now, you can plug in the R-values and get the correspnding w.
[If you prefer "ln", use them to replace "log".]