RANDDISCRETE(val_range,prob_range)
val_range: possible values of the random variable
prob_range: probabilities of the corresponding values in val_range, defaults to equal probabilities
RANDDISCRETE returns one of the values in the val_range. The probabilities for each value are given in the prob_range.
If the sum of all values in prob_range is not one, RANDDISCRETE returns #NUM! If val_range and prob_range are not the same size, RANDDISCRETE returns #NUM! If val_range or prob_range is not a range, RANDDISCRETE returns #VALUE!