Answer:
The correct answer is D. It is not true that cluster sampling uses randomly selected clusters and samples everyone within each cluster.
Step-by-step explanation:
Cluster sampling is a method of collecting samples and statistical data, by means of which a certain group formed by people, things, events, etc., is taken as a sample, which are not considered individually but as part of a whole, which is in turn a proportional representation of the universality of samples available in the field.
Now, since this type of sampling allows to embrace large groups of sample units, data are not always obtained from all the components of the cluster, but from those necessary to be able to quantify the desired statistics.
Answer:
60
Step-by-step explanation:

It is a i think sorry if wrong
A is the correct answer
2 + 3i + (-1) + 7i
1 + 10i
Answer:
C
Step-by-step explanation:
Coterminal angles are angles that have a common terminal side.
So, given an angle θ, its coterminal angles will always be ±360°. This can be repeated.
We have a 645° angle.
Therefore, all values of the equation:

Where <em>n</em> is an integer is coterminal with our original angle.
Letting <em>n</em> = 1 and using the negative case, we acquire:

Therefore, an angle measuring 285° is coterminal with a 645° angle.
None of the other options can be reached by adding/subtracting 360.
Therefore, our answer is C.