now when we get to the third and fourth momentsthings get little bit trickierbut they're still concepts that are easy to grasp the third moment is called skewand it is basically measure of how lopsided distribution is you can see in these two examples above thatif have longer tail on the leftnow then that is negative skewand if have longer tail on the right thenthat' positive skew the dotted lines show what the shape of normal distribution would look like without skew the dotted line out on the left side then end up with negative skewor on the other sidea positive skew in that example okso that' all skew is it' basically stretching out the tail on one side or the otherand it is measure of how lopsidedor how skewed distribution is