Answer:
Part 1) The shape is a trapezoid
Part 2) The perimeter is
or approximately 
Part 3) The area is 
Step-by-step explanation:
step 1
Plot the figure to better understand the problem
we have
A(-28,2),B(-21,-22),C(27,-8),D(-4,9)
using a graphing tool
The shape is a trapezoid
see the attached figure
step 2
Find the perimeter
we know that
The perimeter of the trapezoid is equal to

the formula to calculate the distance between two points is equal to

Find the distance AB
we have
A(-28,2),B(-21,-22)
substitute in the formula




Find the distance BC
we have
B(-21,-22),C(27,-8)
substitute in the formula




Find the distance CD
we have
C(27,-8),D(-4,9)
substitute in the formula




Find the distance AD
we have
A(-28,2),D(-4,9)
substitute in the formula




Find the perimeter


simplify
----> exact value

therefore
The perimeter is
or approximately 
step 3
Find the area
The area of trapezoid is equal to
![A=\frac{1}{2}[BC+AD]AB](https://tex.z-dn.net/?f=A%3D%5Cfrac%7B1%7D%7B2%7D%5BBC%2BAD%5DAB)
substitute the given values
![A=\frac{1}{2}[50+25]25=937.5\ units^2](https://tex.z-dn.net/?f=A%3D%5Cfrac%7B1%7D%7B2%7D%5B50%2B25%5D25%3D937.5%5C%20units%5E2)
Answer:
The 99% confidence interval of the population mean for the weights of adult elephants is between 12,475 pounds and 12,637 pounds.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 10 - 1 = 9
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 9 degrees of freedom(y-axis) and a confidence level of
. So we have T = 3.25
The margin of error is:
M = T*s = 3.25*25 = 81
In which s is the standard deviation of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 12,556 - 81 = 12,475 pounds
The upper end of the interval is the sample mean added to M. So it is 12,556 + 81 = 12,637 pounds.
The 99% confidence interval of the population mean for the weights of adult elephants is between 12,475 pounds and 12,637 pounds.
D. The x and y values are both negative
Y^2-9^2
(y-9)(y+9)
To see if its right:
y*y+y*9-9*y-9*9
y^2+9y-9y-81
y^2-9^2