Generates a random normally-distributed number with specified mean and standard deviation.
randNorm(µ,σ,[n])
Press:
- MATH to access the math menu.
- LEFT to access the PRB submenu.
- 6 to select randNorm(, or use arrows.
TI-83/84/+/SE
2 bytes
randNorm(µ,σ) generates a normally-distributed pseudorandom number with mean µ and standard deviation σ. The result returned will most probably be within the range µ±3σ. randNorm(µ,σ,n) generates a list of n normally-distributed pseudorandom numbers with mean µ and standard deviation σ.
seed→rand affects the output of randNorm(.
0→rand
0
randNorm(0,1)
-1.585709623
randNorm(0,1,3)
{-1.330473604 1.05074514 -.0368606663}
Although a theoretical normally distributed variable could take on any real value, numbers on a calculator have a limited precision, which leads to a maximum range of approximately µ±7.02σ for values of randNorm(.
Optimization
When the mean is 0 and the standard deviation 1, invNorm(rand) and invNorm(rand(N)) save space over randNorm(0,1) and randNorm(0,1,N) respectively.
Formulas
The value of randNorm( for a given seed can be expressed in terms of rand:
randNorm(µ,σ)=µ-σinvNorm(rand
This is identical to the output of randNorm( in the sense that for the same seed, both expressions will generate the same random numbers.
Related Commands
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