Answer:
A sample of 16577 is required.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the z-score that has a p-value of 
.
The margin of error is of:
99% confidence level
So 
, z is the value of Z that has a p-value of 
, so 
.
She wants to estimate the proportion using a 99% confidence interval with a margin of error of at most 0.01. How large a sample size would be required?
We have no estimation for the proportion, and thus we use 
, which is when the largest sample size will be needed.
The sample size is n for which M = 0.01. So
Rounding up:
A sample of 16577 is required.
Vertical angles are equal, so
.. 3x +8 = 5x -20
.. 28 = 2x . . . . . . . . add 20-3x
.. 14 = x . . . . . . . . . . divide by 2
Each of the vertical angles is 3*14 +8 = 50°, so the supplementary one is 130°.
.. 5*14 +4y = 130
.. 4y = 60 . . . . . . . . subtract 70
.. y = 15 . . . . . . . . . . divide by 4
The values of interest are
.. x = 14
.. y = 15
Question 3. the answer is 18
4. the answer is 3x+3y
