We spent the whole class mulling over our current datasets, and re-calculating manually the standard deviations for all our datasets to ensure that we have the correct values. We then used these standard deviations to calculate the z-scores for all datasets, and concluded that the spike in the astronauts' birthdays in March is the most significant amongst our numbers. Jared was amazed that two disparate datasets produced the same standard deviation, an excellent example of statistics!