To receive full credit on the condence intervals. you must show each of the following: a. The critical value (3 points) b. The error bound (round answers to at least hundredths) (3 points) c. The minimum and maximum numbers of the interval (3 points each) To receive full credit on the interpretations, you must include information about the specific problem. When nding the sample size, remember to round all answers up to the next highest whole number. Show all work for partial credit! 1.) As part of an environmental studies class project, students measured the circumferences of a random sample of 38 blue spruce trees near Brainard Lake. Colorado. The sample mean circumference was )7 = 27.4 inches. Assume that a is known to be 6.1 inches. a.) Find a 90% condence interval for the population mean circumference of all blue spruce trees near this lake. (12 points) b.) Interpret the meaning of the condence interval in the context of this problem. (2 points)