MARGIN OF ERROR BETWEEN SIMPLE RANDOM SAMPLING AND STRATIFIED SAMPLING
The sample is a small part or quantity intended to show what the whole is like. While the sampling technique is part of the statistical method related to sampling methods. The sampling method that can be used for sampling includes Simple Random sampling and Stratified Sampling. A simple random sample is a subset of a statistical population in which each member of the subset has an equal probability of being chosen. Stratified Sampling is a way of sampling by paying attention to the strata (levels) in the population. Both of these sampling methods were compared to obtain a smaller margin of error in the Body Mass Index (BMI) data of the College Student of Health Faculty, Nahdlatul Ulama University, Surabaya. The confidence level used is 99%, 95% and 90% with each sample number as many as 634 samples, 252 samples and 88 samples. The results show that as the sample size increases, the margin of error decreases. Variance in the Stratified Sampling technique is smaller than the variance in Simple Random sampling. So that it can be stated that descriptively, the Stratified Sampling technique is more effective than the Simple Random sampling technique.