3. The campus at Joliet Junior College has a lake. A student use a Secchi disk to measure the clarity of the lake's water by lowering the disk into the water and measuring the distance below the water surface at which the disk is no longer visible. The following measurements (in inches) were taken on the lake at various points in time over the course of a year. 82 64 62 66 68 43 38 26 68 56 54 66 a. (2 pts) Determine a point estimate for the population mean Secchi disk measurement. b. (2 pts) Verify that the requirements for constructing a confidence interval for / are satisfied. c. (2 pts) Construct 95% confidence interval for the mean Secchi disk measurement