INDE 2333 Chapter Notes - Chapter 1: Random Variable, Observational Study, Statistical Inference
3 Jun 2017
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Statistics science that helps people make decisions in a situation where there are a lot of variables. Variability observing a system that does not produce the same result every time. Random variable a measurement that displays variability. Dot diagram a plot that is good at showing the middle and variability. Census survey taken from entire population. Sample survey taken from smaller portion of population. Good data collection leads to simpler analysis and more accurate understanding of the population or process being studied. Methods for collecting data: retrospective study using historical data. Relevant data may be missing: observational study gather data by pure observation. Observer does not disturb the process/population: designed experiments make deliberate changes in a controlled experiment and records the results. Most important data collection method in engineering. Observing process over time: time series plot used when data is collected over time. Overcontrol/tampering adjustments to a process based on random disturbances can actually increase the variation of the process.
