Normal Distribution: Areas to the Left and Right of x 1.4 2008/06/06 14:39:08 GMT-5 2008/07/21 03:01:19.622 GMT-5 Barbara Illowsky illowskybarbara@deanza.edu Susan Dean deansusan@deanza.edu Connexions cnx@cnx.org elementary statistics The arrow in the graph below points to the area to the left of x. This area is represented by the probability P ( X x ) . Normal tables, computers, and calculators provide or calculate the probability P ( X x ) . The area to the right is then P ( X x ) = 1 - P ( X x ) . Remember, P ( X x ) = Area to the left of the vertical line through x. P ( X x ) = 1 - P ( X x ) = . Area to the right of the vertical line through x P ( X x ) is the same as P ( X x ) and P ( X x ) is the same as P ( X x ) for continuous distributions.