Relationship between perception of coeval friend’s role and religiousness of students in Madrasah Aliyah X in Bandung regency.

Abstract

Control diagram of standard deviation σ is one of variable control diagrams used to control dispersion process. This control diagram is built by the assumption that the data is in normal distribution with the minimum μ and variants σ2. In phase I, control diagram of standard deviation formed by standard deviation predicted by the data taken during K period when each of them is n-size. There are 3 predictors of standard deviation based on ,   and  . If there is a outlier data, the standard deviation predictors can be unbalanced, so the power of control diagram of standard deviation becomes bad.  This research describes control diagram of standard deviation phase I that has the quality of Robust with its function to filter the data, so standard deviation predictor can be obtained by the method of   dan  . The result of robust predictor on phase I used to control process of next phase (phase II). This method is implemented on power data of thread in PT. World Yamatex Spinning Mills II Karawang regency. The results show that the predictor   is bigger than  .