<span>1) We are given that PA = PB, so PA ≅ PB by the definition of the radius.
</span>When you draw a perpendicular to a segment AB, you take the compass, point it at A and draw an arc of size AB, then you do the same pointing the compass on B. Point P will be one of the intersections of those two arcs. Therefore PA and PB correspond to the radii of the arcs, which were taken both equal to AB, therefore they are congruent.
2) We know that angles PCA and PCB are right angles by the definition of perpendicular.
Perpendicularity is the relation between two lines that meet at a right angle. Since we know that PC is perpendicular to AB by construction, ∠PCA and ∠PCB are right angles.
3) PC ≅ PC by the reflexive property congruence.
The reflexive property congruence states that any shape is congruent to itself.
4) So, triangle ACP is congruent to triangle BCP by HL, and AC ≅ BC by CPCTC (corresponding parts of congruent triangles are congruent).
CPCTC states that if two triangles are congruent, then all of the corresponding sides and angles are congruent. Since ΔACP ≡ ΔBCP, then the corresponding sides AC and BC are congruent.
5) Since PC is perpendicular to and bisects AB, P is on the perpendicular bisector of AB by the definition of the perpendicular bisector.
<span>The perpendicular bisector of a segment is a line that cuts the segment into two equal parts (bisector) and that forms with the segment a right angle (perpendicular). Any point on the perpendicular bisector has the same distance from the segment's extremities. PC has exactly the characteristics of a perpendicular bisector of AB. </span>
The best estimate of the population means is always the sample mean. We have the sample values, using them we can find the sample mean.
The sum of the sampled rates = 248
Sample Size = 10
Mean value of the sample = Sum of Sample Rate/Sample Size
So,
Mean of the sample = 248/10 = 24.8
Therefore, we can say that the best estimate for the population mean is 24.8
Answer:
x = 48/7
Step-by-step explanation:
There's two good ways to do this problem.
Option 1:
Translate "x varies directly as y" into the equation y=kx
Then you have to find k. After you "reset" your y=kx equation, fill in k and then solve for x. See image.
Option 2:
Translate "varies directly" into a proportion, which is two fractions equal to each other:
x/y = x/y
Fill in the three numbers given and cross multiply and solve to find the fourth number. See image.
Answer:
144°
Step-by-step explanation:
step 1
Find the measure of the central angle of the regular pentagon
Divide 360 degrees by 5 (the number of sides)
Let
c----> the center of the pentagon
we know that
m∠ECA=72°
m∠ACB=72°
therefore
m∠ECB=m∠ECA+m∠ACB
substitute the values
m∠ECB=72°+72°=144°
The measure of angle ECB is equal to the degrees that the pentagon rotate
Answer:
Sample size n = 1382
so correct option is D) 1382
Step-by-step explanation:
given data
confidence level = 99 %
margin of error = 3%
probability = 25 %
to find out
How large a sample size needed
solution
we know here P = 25 %
so 1 - P = 1 - 0.25
1 - P = 0.75
and we know E margin of error is 0.03 so value of Z for 99%
α = 1 - 99% = 1 - 0.99
α = 0.01
and 
= 
= 0.005
so Z is here
= 2.576
so
sample size will be
Sample size n = 
put here value
Sample size n = (\frac{2.576}{0.03})^2 * 0.25 * 0.75
Sample size n = 1382
so correct option is D) 1382
