1. The problem statement, all variables and given/known data Find k such that the area between the function and the x-axis, bounded by x = 1 and x = k, is equal to 100 square units. 2. Relevant equations y = 4e^(x/5) 3. The attempt at a solution 1. Wrote the problem as the definite integral from 1 to k of 4e^(x/5)dx = 100. 2. Antidifferentiated to obtain 20e^(x/5). 3. Made substitutions into F(b) - F(a) = 100 to obtain 20e^(k/5) - 20e^(1/5) = 100. 4. Solved for k and got k = 5*ln(5) + 1. 5. At that point I thought I had it all figured out, but when I did 20e^((5*ln(5) + 1)/5) - 20e^(1/5) to check I get 97.7122207 as the result. What am I doing wrong here? Any help would be appreciated.