Problems with normal probabilities
The position of the graphically
represented keys can be found by moving your mouse on top of the graphic.
The row of round buttons at the top do not count as a row. Row 1 starts
with .
Computing probabilities  
The problem is finding P(X <b) where X is a random variance with a specified mean and standard deviation.  


The problem is finding P(0< X <b) where X is a random variance with a specified mean and standard deviation.  


The problem is finding P( X > b) where X is a random variance with a specified mean and standard deviation.  

Worked Out Examples
In the following examples, we list the exact
key sequence used to find the answer. We will list the keys by the main symbol
on the key. In parentheses, we will list a helpful mnemonic, e.g. we will list
e^{x} as
(e^{x}).
Question 1: Let X be a random variable with m=50 and s=4. Compute P(X < 51).  
Solution: (DISTR) ( P( ) . You should get 0.59871 as the first five decimal places.  
Question 2: Let X be a random variable with m=10 and s=8. Compute P(X >12).  
Solution: (DISTR) (R( ) . You should get 0.40129 as the first five decimal places.  
Question 3: Let X be a random variable with
m=100
and s=12. P(100 < X < 103). 

Solution: (DISTR) ( Q( ) . You should get 0.09871 as the first five decimal places.  
Notice that P will always be 50 more than Q. Also notice that P and R will add up to one. 
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