using continous compound interest formula to find the indicated value

Question

A= 99000
P= 72466
R= 7.8%
T= ?

Answer 1

Continuous compound interest formula:
A=Pe^RT
to find t, take log (natural log) on both sides
ln(A)=ln(P)+RT
Solve for T (about 4 years)
R should be written as a fraction (0.078)