Create a Mixture of Gaussians in Excel Method One: Random Variable Approach
The model will have three inputs σ1, σ2 , and q (assume means of zero): Use the inverse transform method to create two series of normal variables with standard deviations of σ1 and σ2 , each involving a series of calls to RAND(). Then, use a third series of calls to RAND () to determine which of the two normal variables just created make up the mixture,
- Generate at least 65,000 numbers.
- Calculate the mean, standard deviation, and excess kurtosis for all three distributions.
- Check the resultant mixture versus the theoretical formulas for convergence.
This approach directly models the mixed Gaussian density function rather than the random numbers themselves.
- The model will have three inputs (assume means of zero): σ1, σ2, and q.
- Choose the discretized x-space carefully.
- Graph all three distributions.
- Use the density approach formulas for the moments (3.64)-(3.66) and check them against the theoretical values. If the match is poor, it could be due to a poor choice of the discretized x-space.