How To Find Point Estimate With Lower And Upper Bound. In our example the point estimate was 0.2 and the margin of error was 0.143, then: 0.20, upper bound 0.40, n = 200 4.

So the lower bound is halfway between 27.5 and 27.6 which is 27.55cm. To find the lower bound of x/y, divide the lower bound of x (numerator) by the upper bound of y (denominator). Aside from determining the point estimate of the population mean, you also have to determine the margin of error when the lower bound of your confidence interval is 125.8 and the upper bound of your confidence interval is 152.6.