A confidence interval for a population mean has length 26. a. Determine the margin of error. b. If the sample mean is 60, obtain the confidence interval. c. Construct a graph that illustrates your results. a. The margin of error is 13 . (Type an integer or a decimal. Do not round.) b. The confidence interval for u is from 47 to 73. (Type integers or decimals. Do not round.) c. Choose the correct graph below. O A. OB. Confidence E Interval CI E E 38 70 38 70 O C. OD. O Confidence Interval E E E CI 44 76 44 76