According to the residuals and their variances, the Baarda test statistic b.

This paper discusses four problems when hypothesis test is used in management:Null hy-pothesis for one-sided tests;the confidence level selection;Statement for decision role and theprobability calculation for the test statistics.

Using this result, the critical value of Fisher test statistics can be calculated simply and directly when the sample size is larger.

The sample fractile and equivariant estimators of scale parameter of the extreme are used to construct the new test statistic——Z~* type statistic.

A new test statistic is given.

A method of detection of outliers from the exponential distribution is given by sample fractile to construct test statistics.

Based on the monitoring data from three water quality inspection stations in the Yongjiang River,the space-time change tendency of the water quality was analyzed using seasonal Kendall examination method and probabilistic method.

For the nonlinear autoregressive time series model x_t=φ(x_(t-1),x_(t-2),…,x_(t-p))+ε_t with E(ε_t~2)=∞,it is showed that if there existsδ≥1 such that E|ε|~δ<∞,then the distribution ofθ_(L_1),the self-weighted L_1-estimator ofθ,is asymptotically normal and the Wald test statistic has the ordinary X~2 distribution.