Final answer:
To find the point estimate of the population mean from a confidence interval, average the upper and lower bounds. To find the margin of error, subtract the point estimate from the upper bound or take half the difference between the upper and lower bounds.
Step-by-step explanation:
To determine the point estimate of the population mean from a confidence interval, you can calculate the average of the lower bound and the upper bound of the interval. Without the explicit lower and upper bounds provided in the question, let's use an example where the lower bound is 67.18 and the upper bound is 68.82. You would compute the point estimate by finding the midpoint: (67.18 + 68.82) / 2 = 68.
The margin of error (EBM) can be found two ways. If the sample mean (point estimate) is known, subtract the point estimate from the upper bound of the confidence interval. Using the same example, if the point estimate is 68, then EBM would be 68.82 - 68 = 0.82. If the sample mean is unknown, you can find the EBM by calculating half of the difference between the upper and lower bounds: (68.82 - 67.18) / 2 = 0.82.
When creating a confidence interval, the general form used is (point estimate − EBM, point estimate + EBM), where the EBM depends on the confidence level and, in some cases, the standard error of the mean or sample size, depending on whether the population standard deviation is known or unknown.