Answer:
b)Add the equations to eliminate x.
Step-by-step explanation:
y= x+20
y= - x+2
Result of the addition: (-x cancels x)
2y = 22
y =11
11=x +20 -9 = x
11=9+2
11 = -9 +20
Answer:
21% probability you will hit a green light on monday and a red light on tuesday
Step-by-step explanation:
When two events, A and B, are independent, we have that:
In this problem, we have that:
Event A: Green light on monday.
Event B: Red light on tuesday.
The probability that we encounter a green light at the corner of college and main is 0.35
This means that 
The probability that we encounter a red light is 0.61:
This means that 
These events are independent, that is, the light color on Tuesday is independent of the color on Monday. So
21% probability you will hit a green light on monday and a red light on tuesday
Answer:
Step-by-step explanation:
That's B: the surface area.
The volume of the sphere is V = (4/3)πr³; A = 4πr² happens to be the derivative of V with respect to r.
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.
