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. (2,10)
Step-by-step explanation:
5x + y = 20
y = 5x
The second equation is already solved for y, so substitute 5x for y in the first equation to find x.
5x + 5x = 20
10x = 20
x = 2
Now substitute 2 for x in the second original equation to find y.
y = 5(2)
y = 10
Answer: (2, 10) which is A.
Answer:
C. y=-2/3x +6
Step-by-step explanation:
The formula for a linear equation is y=mx+b, where m= the slope and b is the y-intercept. The slope is -2/3 because slope equals rise over run and the line goes down 2 then right 3. Finally, the y-intercept must be 6 because the line intersects with the y-axis at the value of 6.
Remember, to be a function, all elements in the domain should correspond to one element in the range.
The domain is the x coordinate, range is the y coordinate.
The domain we can solve for as the set {4.2, 5, 7}. The range is the set {0, 1.5, 2.2, 4.8}.
But we see that an element in the domain corresponds to more than one element in the range, thus making it not a function.