Question

there are 16 bactiria in a beaker and four hours later there are 228 bacteria in the beaker. what is the rate of change per hour in the number of bactiria

Answer 1

Write and solve the appropriate exponential equation:

228 = 16(r)^4, where r is the change per hour in the number of bacteria:

228

------ = r^4     =   14.25.  

 16

Taking the fourth root of both sides, we get:  r = 1.94 (answer)

Answer 2

Initial number of bacteria = 16

Final number of bacteria after 4 hours = 228

So, bacteria increased by = $228-16=212$

So per hour the bacteria increased by = $\frac{212}{4}$ = 53

Hence, the bacteria increased by 53 per hour.