Answer: 18
Step-by-step explanation:
The formula to find the minimum sample size is given by :_
, where 
= population standard deviation.
z*= critical z-value.
E= Margin of error.
Given : 
E= ± 8
We know that critical value corresponding to 99% confidence level = z*=2.576 [Using z-table]
Then, the required sample size would be :
[Round to next integer.]
Hence, the required minimum sample size = 18
Answer:
A
Step-by-step explanation:
For a graph to be representative of a proportional relationship, it must meet the following criteria:
1) It is a straight line.
2) It passes through the origin point (0,0).
3) It is neither horizontal nor vertical*.
We can see that D is not a line. So, D is not a proportional relationship.
We can also see that B and C are vertical and horizontal, respectively. They also do not cross the origin.
The only choice that is a straight line and also crosses through the origin point is A.
So, our answer is A.
And we're done!
*Note: Vertical lines are not proportional because they are not a function.
Horizontal lines are not proportional because they has a constant of proportionality of 0, which can't be the case.
