The following represent the number of accidents that occurred at five randomly selected pedestrian crossings in Cape Town in the past year: 3, 7, 2, 3, 5. Estimate the standard deviation of accidents...

The following represent the number of accidents that occurred at five randomly selected pedestrian crossings in Cape Town in the past year: 3, 7, 2, 3, 5.

Estimate the standard deviation of accidents at pedestrian crossings in the whole of Cape Town over the same period.