Answer:
D. cluster
Step-by-step explanation:
Convenience: Based on availability.
Systematic: The first element is sorted randomly, then the others follow a pattern.
Random: Each member of a sample has the same probability of being sorted.
Cluster: Each group is cluster, and when a cluster is sorted, every member of the group is sample. This is the correct answer.
Stratified: Population is divided into groups and then members from these groups are sorted.
Because fractions are part of a number
Answer:
The equation is 
Step-by-step explanation:
The initial value or "b" is 2 and the slope is
or just 2
Using proportions, it is found that the differential equation which describes the growth of the pigeon population is given by:

<h3>What is a proportion?</h3>
A proportion is a fraction of a total amount, and the measures are related using a rule of three.
In this problem, considering the initial population and the population one week later, the rate of growth is given by:
k = 9/6 = 1.5.
The standard differential equation for population growth is:

Hence:

More can be learned about proportions at brainly.com/question/24372153
#SPJ1