I'll do part (a) to get you started.
The angle 'a' pairs up with the 123 degree angle as a corresponding angle pair. Due to the parallel lines, the corresponding angles are congruent. Therefore a = 123.
We also see that b = 123 as well since a = b (they are vertical angles).
Notice how angle c is adjacent to the 123 degree angle. These two angles form a straight line, so they must add to 180 degrees.
c+123 = 180
c = 180-123
c = 57
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To summarize, we have these three angles
a = 123
b = 123
c = 57
Complete question:
Assume that different groups of couples use a particular method of gender selection and each couple gives birth to one baby this mention is designed to increase the likelihood that each baby will be a girl, but assume that the method has no effect so the probability of a girl is 0.5. Assume that the group consists of 36 couples.
A) Find the mean and standard deviation for the number of girls in groups of 36 births.
B) Use the range rule of thumb to find the values separating results that are significantly low and significantly high.
C) Is the result of 33 girls significantly high? A result of 33 girls would suggest the method is effective or is not effective?
Answer:
a) mean = 18
Standard deviation =3
b) low range = 12
High range = 24
c) The result of 33 girls is significantly high. Yes, the method is effective.
Step-by-step explanation:
Given:
p = 0.5
n = 36
a) The mean is the product of n and p
Mean u = np
u = 36 * 0.5 = 18
The standard deviation is the square root of the product of n and p&q.
S.d ó = 


b) To find the range rule of thumb:
• For low range
Low range = u - 2ó
= 18 - (2 * 3)
= 12
• High range
= u + 2ó
= 18 + (2*3)
= 24
c) The result is significantly high, because 33 is greater than 24 girls.
A result of 33 girls would prove the method as effective.
The formula required is:

where A is the amount after t years of the principal P invested at an annual interest rate r (expressed as a decimal fraction) compounded n times per year.
Plugging in the given values, we get:

The final amount is $22,096.17
25/8 when using the butterfly method
X= 8/3 :)) hope this helps !