Tham khảo tài liệu 'engineering statistics handbook episode 2 part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | . t Distribution Other Probability Functions Since the t distribution is typically used to develop hypothesis tests and confidence intervals and rarely for modeling applications we omit the formulas and plots for the hazard cumulative hazard survival and inverse survival probability functions. Common Statistics Mean 0 It is undefined for 1 equal to 1. Median 0 Mode 0 Range Infinity in both directions. Standard Deviation ỉ 1 y y-2 It is undefined for V equal to 1 or 2. Coefficient of Undefined Variation Skewness 0. It is undefined for V less than or equal to 3. However the t distribution is symmetric in all cases. Kurtosis 3 2 Ì - 4 It is undefined for V less than or equal to 4. Parameter Estimation Since the t distribution is typically used to develop hypothesis tests and confidence intervals and rarely for modeling applications we omit any discussion of parameter estimation. Comments The t distribution is used in many cases for the critical regions for hypothesis tests and in determining confidence intervals. The most common example is testing if data are consistent with the assumed process mean. Software Most general purpose statistical software programs including Dataplot support at least some of the probability functions for the t distribution. NIST SEMATECH HOME tools AIDS FsEARCH 0ACK NEXT http div898 handbook eda section3 4 of 4 5 1 2006 9 57 57 AM . F Distribution ENGINEERING STATISTICS HANDBOOK hW tools raids lỉEÂtCH BACK Nixf 1. Exploratory Data Analysis . EDA Techniques . Probability Distributions . Gallery of Distributions Distribution Probability Density Function The F distribution is the ratio of two chi-square distributions with degrees of freedom and ỉ respectively where each chi-square has first been divided by its degrees of freedom. The formula for the probability density function of the F distribution is where and 2 are the shape parameters and r is the gamma function. The
