Finding the mean and variance for discrete probability distributions: an alternative approach using cumulative and decumulative probabilities
James R. Lackritz, Ronald E. Shiffler · International Journal of Mathematical Education in Science and Technology · 1990
The paper derives alternative formulae for the mean and variance for discrete probability distributions using cumulative and decumulative probabilities. The new formulae provide less complexity, in that instead of the standard weighted formulae around the x and x 2 terms, no x term is used in finding the mean, and only x instead of x 2 is used in the variance term. Examples illustrate this.