The mean is 39.27

The median is 38

The standard deviation is 11.86

The observation 12 is a possible outlier. The outlier does NOT affect the median because the median is a resistant measure of the center. The outlier does affect the mean. Since the distribution is left–skewed, the outlier decreases the mean. The outlier does affect the standard deviation. Since the is far from the mean, the outlier increases the standard deviation.