A Fossil Was Discovered That Had About 70% of The ${ } ^ { 14 } \mathrm { C }$

Short Answer

A fossil was discovered that had about 70% of the ${ } ^ { 14 } \mathrm { C }$ level found today in living matter. Given that the decay constant for ${ } ^ { 14 } \mathrm { C }$ is 0.00012, determine the age of the fossil.
Enter your answer exactly as just $\frac { \ln a } { \mathrm {~b} }$ where a is a real number to one decimal place and b is a real number to 5 decimal places.