The times, in seconds, taken by 12 athletes to run 400 m are
45.2,46.9,46.1,46.2,45.4,45.1,47.8,45.4,45.5,46.1,46.4,45.745.2,46.9,46.1,46.2,45.4,45.1,47.8,45.4,45.5,46.1,46.4,45.745.2,46.9,46.1,46.2,45.4,45.1,47.8,45.4,45.5,46.1,46.4,45.7.
Find the mean.
Find the sample standard deviation.
Find the median and quartiles.