Totals - DRAFT VERSION

A total is the sum of the values of a variable across observations, often weighted (by sample weights to estimate the sum of values across the whole population. Sometimes totals hold inherent interest themselves, as when a policy-maker may try to estimate the number of girls in schools in a state or nation. More often, totals are estimates in support of other statistics. Many statistics can be viewed as a function of sample totals. For example, the mean is the ratio of the sum of a variable's values, divided by the sum of sample inclusion indicators (or the weighted values divided by the sum of weights). Many statistical procedures use population totals in estimation, including, Means Correlations Frequencies, and Regression /ul> One advantage of building these procedures on top of estimates of totals is that the variance of population totals can be effectively estimated via Taylor-series expansion using a common algorithm.