Final answer:
To find the approximate time it will take for the sample to have approximately 65,459 bacteria, we can solve the equation A = 256e^(1.386t) = 65,459 for t. The approximate time is 4.42 hours.
Step-by-step explanation:
To find the approximate time it will take for the sample to have approximately 65,459 bacteria, we can set up the equation A = 256e^(1.386t) equal to 65,459 and solve for t. 
 
65,459 = 256e^(1.386t) 
 
Divide both sides by 256: 
 
e^(1.386t) = 65,459 / 256 
 
Take the natural logarithm of both sides: 
 
ln(e^(1.386t)) = ln(65,459 / 256) 
 
Use the property of logarithms to bring the exponent down: 
 
1.386t * ln(e) = ln(65,459 / 256) 
 
ln(e) is equal to 1, so we can simplify: 
 
1.386t = ln(65,459 / 256) 
 
Divide both sides by 1.386 to solve for t: 
 
t = ln(65,459 / 256) / 1.386 
 
Using a calculator, we find that t is approximately 4.42 hours. Therefore, in approximately 4.42 hours, there will be approximately 65,459 bacteria in the sample.