Answer: aA 90% confidence interval for the population proportion of adults in the U.S. who have donated blood in the past two years = (0.163,0.189)
Step-by-step explanation:
Let p = population proportion of adults in the U.S. who have donated blood in the past two years.
Given: A Gallup survey of 2322 adults (at least 18 years old) in the U.S. found that 408 of them have donated blood in the past two years.
Sample size: n= 2322
Sample proportion 
Critical z-value for 90% confidence level : z*=1.645
The confidence interval for population proportion:

A 90% confidence interval for the population proportion of adults in the U.S. who have donated blood in the past two years:

Hence,
Answer:
y = mx + c
m = -4
at y intercept x = 0
(x,y) =(0,-3)
-3 = -4(0) + c
c = -3
therefore the answer is y = -4x + c
The way to find the factores is by seeking the polonomial's roots, or zeros!
To find the roots, we set the polinomial equation to zero:
x^2+16y^2=0
Then we solve this equation:
x^2=-16y^2
This is only true, if x=y=0.
The sum is 160/(1-r)=1280 where r is the common ratio,
1/(1-r)=1280/160=8
Inverting we get 1-r=1/8, r=7/8.