4x-7x= 13
⇒ -3x= 13
⇒ x= 13/(-3)
⇒ x= -13/3
The final answer is x= -13/3~
Answer:
The 95% confidence interval for the true proportion of all voters in the state who favor approval is (0.4384, 0.5050).
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
.
For this problem, we have that:

95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
The lower limit of this interval is:

The upper limit of this interval is:

The 95% confidence interval for the true proportion of all voters in the state who favor approval is (0.4384, 0.5050).
Answer:
1414 kL
Step-by-step explanation:
The volume of the donut-shaped moat is the product of its surface area and depth. The area is the product of its centerline length and its width.
<h3>Moat area</h3>
The diameter of the centerline of the moat is (50 m -5 m) = 45 m. The length of that centerline is ...
C = πd = π(45 m) = 45π m
The area is this length times the width of the moat:
moat area = (45π m)(5 m) = 225π m²
<h3>Moat volume</h3>
The volume is the product of the area and the depth of the moat:
V = Ah = (225π m²)(2 m) = 450π m³ ≈ 1413.72 m³
1 cubic meter is 1000 liters, 1 kiloliter.
The volume of the moat is about 1414 kL.
The true answer is A. all parallelograms are rectangles