Statistical methods are mathematical techniques that use data to analyze, summarize, and draw conclusions about a population or a process. Such methods can help you understand the characteristics, patterns, and variations of your hardware components and products, as well as identify and solve problems related to quality. Descriptive statistics are numerical or graphical summaries of data that show the distribution, central tendency, and dispersion of your hardware measurements or attributes. Examples include mean, median, mode, standard deviation, range, frequency, histogram, or boxplot. Inferential statistics use sample data to make generalizations or predictions about a larger population or a process; for example confidence intervals, hypothesis testing, correlation, or regression. Control charts monitor the variation and stability of a process over time by plotting the data points and the control limits; for example X-bar and R charts, p charts, or CUSUM charts. Design of experiments help you plan, conduct, and analyze experiments that test the effects of different factors or variables on your hardware outcomes or responses; such as factorial designs, response surface designs, or Taguchi designs.