Posted by Walt on .
Can you Check my work please?
Let N(t) be the number of bacteria after t days. Then N(t) = Pa^t for some constants
P and a. Measurements indicate that N(4) = 5600 and N(8) = 362, 000.
b. Write down two equations for P and a, one when t = 4 and the other when t = 8.
c. Use these two equations to compute a and P. Round your values to three signiﬁcant
digits, but be sure to store the more precise values for further calculations
My equations:
Pa^4 = 5600
Pa^8 = 362000
My rounded values:
P=86.1
a=2.84
Thank You For Checking

Math 
Reiny,
Since you are probably using a calculator, do not round off a number if it is to be used again .
Only round off final answers.
I agree with your value of a = 2.84
but a was really 2.835503062..
make use of your memory of your calculator and use that number.
that way I got 86.6298..
which would round off to 86.6
which is a significant difference from you 86.1