3 times 4 is equal to 12
8 times 4 is equal to 32
therefore 3:8 is equal to 12:32
hope this helps
Answer:
The minimum sample size needed is 125.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of 
.
The margin of error is:
For this problem, we have that:
99% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
What minimum sample size would be necessary in order ensure a margin of error of 10 percentage points (or less) if they use the prior estimate that 25 percent of the pick-axes are in need of repair?
This minimum sample size is n.
n is found when 
So
Rounding up
The minimum sample size needed is 125.
Answer:
3 inches
Step-by-step explanation:
(14+2x) × (15+2x) = 2(14×15)
210 +30x +28x + 4x² = 420
4x² + 58x - 210 = 0
2x² + 29x - 105 = 0
2x² + 35x - 6x - 105 = 0
x(2x + 35) - 3(2x + 35) = 0
(x - 3)(2x + 35) = 0
x = 3, -35/2(not possible)
Answer: choice A. 40 liters
====================================
Explanation:
x = number of liters of the 50% alcohol solution
If we have x liters of 50% alcohol, then we have 0.50*x liters of pure alcohol. This is added to 0.90*40 = 36 liters of pure alcohol (from the 90% solution).
So far we have 0.50*x + 36. This expression represents the total amount of pure alcohol. We want a 70% solution, so we want 70% of the total 40+x meaning 0.50*x + 36 is to be set equal to 0.70*(40+x) and we solve for x as shown below
0.50*x + 36 = 0.70*(40+x)
0.50*x + 36 = 0.70*(40)+0.70*(x)
0.50*x + 36 = 28+0.70*x
36 - 28 = 0.70*x - 0.50x
8 = 0.20x
0.20x = 8
x = 8/0.20
x = 40
So that is why the answer is choice A. 40 liters
Let P(a, b) be a point on the coordinate plane. Then the following hold:
i) If a>0, b>0 then P is in the I.Quadrant.
ii) If a<0, b>0 then P is in the II.Quadrant.
iii) If a<0, b<0 then P is in the III.Quadrant.
iv) If a>0, b<0 then P is in the IV.Quadrant.
v) If a=0 and b is positive or negative, then P is on the y-axis.
vi) If b=0 and a is positive or negative, then P is on the x-axis.
Since we have: a=0, and 19 positive, then this point is on the y-axis.
Answer: y-axis
