the answer is D you get this from using simultaneous equations the working out is shown in the photo. ignore the stuff at the top of the page
Do you mean 5 into 50?
10 times if it is 5 into 50.
If it is 50 into 5 then it's 0.1 times, I believe.
X + 3y = 9
3x - 3y = -13
--------------add
4x = - 4
x = -4/4
x = -1
x + 3y = 9
-1 + 3y = 9
3y = 9 + 1
3y = 10
y = 10/3
solution (-1,10/3)
Answer:
a) 96% CI: 
b) If we estimate that the fraction of voters is 0.57, we can claim with 96% confidence that the error is equal or less than 0.06 from the estimated proportion.
Step-by-step explanation:
The proportion of the sample is

The standard deviation of the sample proportion is

For a 96% CI, the z-value is z=1.751.
Then, the 96% CI can be written as:

b) If we estimate that the fraction of voters is 0.57, we can claim with 96% confidence that the error is equal or less than 0.06 from the estimated proportion.