A study by Morgan and coworkers used genetically modified white blood cells to treat patients with melanoma who had not responded to standard treatments. In patients in whom the cells were cultured ex vivo for an extended period of time (cohort 1), the cell doubling times were {8.7, 11.9, 10.0} days. In a second group of patients in whom the cells were cultured a shorter period of time (cohort 2), the cell doubling times were {1.4, 1.0, 1.3, 1.0, 1.3, 2.0, 0.6, 0.8, 0.7, 0.9, 1.9} days. In a third group of patients (cohort 3), actively dividing cells were generated by performing a second rapid expansion via active cell transfer. Cell doubling times for cohort 3 were {0.9, 3.3, 1.2, 1.1} days. Calculate the mean and standard deviation within each group.