Normal distribution with CAS
- Hannu Mäkiö
You can solve different problems with normal distribution with CAS with only one function. If randon variable , then the cumulative distribution function is defined by . In Geogebra this function is: or Normal(Mean ,Standard deviation , Variable Value). By default, this gives cumulative distribution. For density you need to add 4th variable = false. For example, you can graph density distribution with command Normal( 10, 2, x, false). But back to cumulative distribution. You can solve problem: , solve with command Normal( 10, 2,13.2 ) Or the problem, where mean is unknow, but probability is given, write equation Normal(x, 2,13.2 )=0.65 and solve it numerically. For this you could also you function InverseNormal( Mean, Standard Deviation,Probability). Same works, when standard deviation is unknown. Normal(11, x,13.2 )=0.65 Which problem is solved by this command? Remember to solve it numerically. Try these out with Geogebra.