Cal. Welfare and Institutions Code § 4648.13

(a) For the purposes of this section, the following definitions apply: (1) “Probability sample or sampling” means a standard statistical methodology by which a sample is selected based on the mathematical theory of probability regarding the occurrence of random events. (2) “Statistical extrapolation” means the methodology whereby an unknown value can be estimated by projecting the results of a probability sample to the universe from which the sample was drawn with a calculated precision. (b) The State Department of Developmental Services and regional centers may utilize probability sampling and statistical extrapolation when conducting fiscal audits of service providers. (c) Probability sampling shall be done using methodologies that are well-accepted by statisticians. (d) Whenever the results of a probability sample are extrapolated, the audit report shall include a clear description of all the following: (1) The universe from which the sample was drawn. (2) The sample size and method used to select the sample. (3) The formulas and calculation procedures used to determine the dollar amount at issue. (4) The confidence level associated with the precision of the extrapolation.