Finding margin or error

Find the margin of error for the 95% confidence interval.

1) N=169 X=107

2. N=230 X=90

If someone could help me figure out how to answer these by 6 that would be great thanks!

Definitions, please.

What is "N"?
What is "X"

Is that really the notation you intend?

What does your text say about these issues?

Have you ever seen this?
\(\displaystyle N = \frac{z^{2}\cdot s^{2}}{d^2}\)

Can you solve for "d"?