Rao, Hartley, and Cochran’s Sampling Scheme: Application

Abstract

This paper takes a look at the Rao, Hartley, and Cochran’s sampling scheme, when it is required to select sample of sizes 4, 6, 12, and 18 with probability proportional to size without replacement sampling (unequal probability sampling without replacement). This is done by using the data from the 2008 Nigeria Demographic and Health Survey (NDHS).

We studied the distribution of women age 15 – 49 years employed in the 12 months preceding the survey by type of employer. Here, we considered self-employed women alone. It is shown how sample of sizes 4, 6, 12, and 18 could be randomly selected from the population of size 36.  Population total and variance were computed with confidence interval constructed for the population total.

For the randomly selected states in this paper, we realized that as the sample size increases, the variance and standard error decreases.

Keywords: Rao, Hartley, and Cochran’s sampling scheme, probability proportional to size without replacement, sample size four, six, twelve, eighteen.