Statistics: Graphing under the normal curve

The class is trying to integrate graphing calculators.  One skill is graphing under a normal curve.  The first step is to draw a normal distribution curve on the graphing calculator..  The link above has the screen shots for each calculation.  Shadenorm shades the specified area.  The TI84 sequence is Shadenorm(lower bound, upper bound, mean, and SD).  The mean for a normal curve is 0 and the standard deviation SD is 1.  To shade the entire normal curve the sequence is Shadenorm(-1E99, 1E99, 1,0) or (-4,4,0,1)  -1E99 or 1-99 represents infinity or is the program on the TI84 for infinity.  I defined the area under a normal curve as having four SDs in either direction from the mean 0.  Left is designated with - and right is +.  These exercises for shading the area under the normal curve and using normcdf to calculate percentage  were very helpful

It took hours and hours to find useful information about how to graph the normal curve and shade under the normal curve.  The exercises are very useful because they have picture!  The information to the right of these screen shots of the shading are normcdf( and calculate percentages.  In order to shade areas under a normal curve you must have the normal curve defined in y=, the window set for X and Y,  before shading.  Once you have y= and the window settings, the sequence is shadenorm(lower bound, upper bound, mean, SD), such as shadenorm(-1E99, -1.67, 0, 1)  Remember to add the boundaries AND the mean (0 for the normal curve) and SD (1 for the normal curve).  The other step I forgot initially was ENTER.  I defined shadenorm( 1.67, 1E99, 0,1) and forgot to hit ENTER.  I kept entering GRAPH.