Math Calculator help
posted by HM .
Assume that a normal distribution has a mean of 21 and a standard deviation of 2.
Use the empirical rule to find the percentage of values that lie above 23.
Now I did this on the Ti 83 by using Normalcdf(5,1) and getting an answer of 0.84 and then 10.84 and I get about 15.9 in percentage but it is showing me wrong.
Help me I am confused.
Where am I going wrong?

assume that a normal distribution of data has a mean of 19 and a standard deviation of 4. Use the 689599.7 rule to find the percentage of values that lie above 31.