For a confidence interval with level C, the value p is equal to (1-C)/2. A 95% confidence interval for the standard normal distribution, then, is the interval (-1.96,1.96), since 95% of the area under the curve falls within this interval. <span>The point estimate for the </span>population proportion<span> is the sample proportion, and the margin of error is the product of the Z value for the desired confidence level (e.g., Z=1.96 for </span>95%<span> confidence) and the standard error of the point </span>
A flat line is equal to 180 degrees, meaning that if you use linear, you can find out that if you subtract 100 from it, it becomes 80, which resembles the X.