| Abstract: | First it is shown that an estimate of the variance of the sample-mean in systematic sampling from a non-autocorrelated population with linear trend, which is published in textbooks, isn't a suitable estimate: It is biased and not dependent on the essential parameter, the slope of the linear trend. In section 2 an unbiased estimate of the variance is given. As estimate of the sample-mean we take the same as usually used in literature. In section 3 a centric estimate of the sample-mean is introduced, which takes into consideration the slope of the trendline. It is shown that this estimate is unbiased; an unbiased estimate of its variance is given. |
