Answer:
0.549 or 54.9%
Step-by-step explanation:
This is a binomial distribution (Bernoulli's experiment), where the probability of “success” (selecting a battery with acceptable voltage) is 0.9 and the probability of “failure” is 0.1
So, the probability of selecting at least 14 acceptable batteries out of 15 is
where <em>C(n, m) are combinations of n elements taken m at a time</em>.
C(15,14) = 15
C(15,15) = 1
so, the probability we are looking for is

First we need to know how many months is 2 years. To answer that we multiply the number of months in a year by 2 and get 48 months.
Every 3 months the population of turtles doubles, but to get how many times the population doubles, you need to divide 48 months by 3 to get 16.
So population of 400 will get <u>doubled</u> 16 times in the following <u>two</u> years.
We construct the following equation where
is the final population,

Hope this helps. :)