The height (in feet) of a sample of trees in the school playground: 12.5, 9.8, 13.5, 11.2, 12.3, 14.2, 11.7, 9.8, 12.6, 10.4 what is the mean and standard deviation? a. mean = 11.8 ft; standard deviation = 4.52 ft b. mean = 13.1 ft; standard deviation = 1.43 ft c. mean = 11.8 ft; standard deviation = 1.43 ft d. mean = 11.8 ft; standard deviation = 4.52 ft