Answer B.
∑fx=1637,∑fx
2
=127663,∑f=21
x
ˉ
=Mean=
∑t
∑fx
=77.95
σ
2
=
∑f
∑fx
2
−(
x
ˉ
)
2
=
21
127663
−(77.95)
2
=2.987
σ=1.728
Answer:
Look for perpendicular lines or corresponding angles or alternate interior angles.
Step-by-step explanation:
When you want to show that a quadrilateral is a parallelogram you need to show that the oposite sides are parallel. In order to show that two segments are parallel there are various theorems and definitions you can use.
1 - Remember that two lines perpendicular to the same segment are parallel.
2 - When two lines are cut by a secant and their alternate interior angles are congruent, then the resulting lines are parallel, I will attach a drawing to illustrate what I am saying.
3 - When two lines are cut by a secant and their CORRESPONDING angles are congruent, then the resulting lines are parallel, I will also attach a drawing to illustrate what I am saying.
The answer would be the first choice. When you reflect a shape across the x-axis, the y coordinates of every points/vertices become of the opposite of what they usually were.
For example, the y coordinate in (1, -5) {{-5 being the y coordinate) once reflected upon the x axis would be (1, 5).
On the other hand, if the y coordinate were positive it would become negative.