Do i use log?

Question

Suppose that y=2-log(100-x)/0.30 can be used to calculate the number of years y for x percent of a population of 759 web-footed sparrows to die. Approximate the percentage (to the nearest whole per cent) of web-footed sparrows that died after 3 years.

Answer 1

y=2-log(100-x)/0.30

y=3

substitute the value of y

 

log(100-x)/0.30=1

 

log(100-x)=0.30

case 1

I assume the log is 10 based

100-x=10^(.3)=2(approx)

 

so x= 98%

 

If log is natural logarithm 

 

l100-x=e^.3=1.35    so =98.65 i.e 99%