Confidence Test Method for Normal Distribution

The normal population characteristics, such as the mean, standard deviation, percentile, percentage and coefficient of variation, are often tested in engineering. Based on the theory of confidence tests, the test methods for normal population characteristics are presented in this paper, which include the strong test, the weak test and the weak-strong test. Compared with the hypothesis tests and sampling inspections for normal distribution, the confidence tests can overcome the disadvantage that to accept a null hypothesis may simply mean that it is not rejected by significance hypothesis tests, and greatly improve the test precision. The confidence tests can also bring more convenience in engineering, as that the tests for the percentile and percentage of normal population that are difficult in hypothesis tests can be easily solved by the present method.