Answer:
x = 5, y = 8, z = -3
Step-by-step explanation:
Opposite sides of a parallelogram are congruent so to find x:
x + 7 = 3x - 3
-2x = -10
x = 5
To find y:
y + 2 = 2y - 6
-y = -8
y = 8
Therefore, z = x - y = 5 - 8 = -3.
Using the z-distribution, it is found that the smallest sample size required is given by:
B) 7 vehicles.
<h3>What is the margin of error for a z-distribution confidence interval?</h3>
It is given by:

In which:
is the population standard deviation.
In this problem, we have a 90% confidence level, hence
, z is the value of Z that has a p-value of
, so the critical value is z = 1.645.
The margin of error and the population standard deviation are given by, respectively:
.
Then, we solve for n to find the needed sample size.






Rounding up, 7 vehicles have to be sampled, hence option B is correct.
More can be learned about the z-distribution at brainly.com/question/25890103
Answer:
The center is at ( (-1, -2) and the radius is 5.
Step-by-step explanation:
X^2 + 2X + Y^2 + 4Y = 20
Complete the square on the x and y terms.
(x + 1)^2 -1 + (y + 2)^2 - 4 = 20
(x + 1)^2 + ( y + 2)^2 = 25 Comparing this with the standard form:
(x - h)^2 + (y - k)^2 = r^2
- the center is at ( (-1, -2) and thr radius is 5.