1. A computer-implemented method of correlating a plurality of uncertain values, comprising: receiving user input, the user input indicating a distribution type and a correlation factor; providing the distribution type and correlation factor for identifying an approximate correlation representation (ACR) histogram from a plurality of ACR histograms based on the distribution type and the correlation factor, the plurality of ACR histograms being stored in computer-readable memory; receiving the ACR histogram; retrieving a first distribution associated with a first uncertain value and a second distribution associated with a second uncertain value from computer-readable memory; processing the ACR histogram, the first distribution and the second distribution to generate a correlation histogram that represents a correlation between the first uncertain value and the second uncertain value; and displaying the correlation histogram on a display.