Given:
Sample proportion = 85% = 0.85.
Confidence level (CL) = 90%.
Confidence interval (CI)

We want the confidence interval to be 5% or 0.05. Therefore

Because this number is less than 1, a default sample size of 30 (for the normal distribution) is recommended.
Answer: 30
The sum of probability for an event happening and not happening must be equal to 1 because there is a 100% chance that one or the other will occur.
So the probability on not drawing a quarter:
P(!Q)=1-4/5
P(!Q)=5/5-4/5
P(!Q)=1/5
As a percentage:
p/100=1/5
p=100/5
p=20%
Answer is A) -1 because it they are parallel then they have the same slope. If the green line has a -1 slope so does the red line
The answer is 14.50. Hope that helped