101 Concepts for the Level I Exam

A distribution is said to be **symmetrical** when the distribution on either side of the mean is a mirror image of the other. In a symmetrical distribution, mean = median = mode.

If a distribution is non-symmetrical, it is said to be skewed. Skewness can be negative or positive.

A **positively skewed distribution** has a long tail on the right side, which means that there will be frequent small losses and few large gains. Here the mean > median >mode. The extreme values affect the mean the most which is pulled to the right. They affect the mode the least.

A **negatively skewed distribution** has a long tail on the left side, which means that there will be frequent small gains and few large losses. Here the mean < median < mode. The extreme values affect the mean the most which is pulled to the left. They affect the mode the least.