Computing areas under the Normal Curve with the TI-83

Example:
 

normalcdf(0,2)                 .4772499375

(The area from 0 to 2 is .477... or 47.72%)

You can even specify the average and standard deviation of the curve, i.e.
 

normalcdf(44.5,55.5,50,5)                 .7286677973

(The area under a normal curve centered at 50 with SD 5, from 44.5 to 55.5 is about 72.87%)