1. A computer-readable medium storing therein a data analyzing program that causes a computer, which has a memory device storing a set of measured values that include a set of positive case measured values for which an objective variable for an explanatory variable group of one or more explanatory variables represents a positive case and a set of negative case measured values for which the objective variable for the explanatory variable group represents a negative case, to execute a process, the process comprising: extracting randomly, a positive case measured value group and a negative case measured value group from the set of measured values such that the positive case measured values and the negative case measured values extracted are equivalent in number; and generating based on the positive case measured value group and the negative case measured value group extracted at the extracting, a prediction equation that predicts the objective variable for a prediction algorithm.