In circle O, AC and BD are diameters.
1 answer:
Answer:
mArc A B = 120° (C)
Step-by-step explanation:
Question:
In circle O, AC and BD are diameters.
Circle O is shown. Line segments B D and A C are diameters. A radius is drawn to cut angle D O C into 2 equal angle measures of x. Angles A O D and B O C also have angle measure x.
What is mArc A B?
a)72°
b) 108°
c) 120°
d) 144°
Solution:
Find attached the diagram of the question.
Let P be the radius drawn to cut angle D O C into 2 equal angle measures of x
From the diagram,
m Arc AOC = 180° (sum of angle in a semicircle)
∠AOD + ∠DOP + ∠COP = 180° (sum of angles on a straight line)
x° +x° + x° =180°
3x = 180
x = 180/3
x = 60°
m Arc DOB = 180° (sum of angle in a semicircle)
∠AOB + ∠AOD = 180° (sum of angles on a straight line)
∠AOB + x° = 180
∠AOB + 60° = 180°
∠AOB = 180°-60°
∠AOB = 120°
mArc A B = 120°
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Answer:
n=1705
Step-by-step explanation:
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
Assuming the X follows a normal distribution
And the distribution for is:
We know that the margin of error for a confidence interval is given by:
(1)
The next step would be find the value of ,
and
Using the normal standard table, excel or a calculator we see that:
If we solve for n from formula (1) we got:
And we have everything to replace into the formula:
And if we round up the answer we see that the value of n to ensure the margin of error required mm is n=1705.