Use the normalcdf function of the TI calculator to find the area of a shaded region - for this example we find the area to the left of 85 - the syntax is
normalcdf(lower bound, upper bound, mean, standard deviation)
find the area bounded by the normal curve between 85 and 115 - that is, find the probability that a score will be between 85 and 115:
P(85 < X < 115) >>>>> normalcdf(85, 115, 100, 15)
find the area bounded by the normal curve and to the right of the score 115 - that is find
P(X > 115) >>>>>>> normalcdf(115, E99, 100, 15)
find the z score that corresponds to a given LEFT cumulative area - TI returns a z score that cuts off a LEFT cumulative area -
you can find a z score when you know the area to its RIGHT by first determining the area to the LEFT - and use that as the area value in the invNORM function -
