t-distributiont分布t-testt检验tabulation method划记法test of normality正态性检验test of one-sided单侧检验test of one-tailed单尾检验test of significance显著性检验test of two-sided双侧检验test of two-tailed双尾检验theoretical frequency理论频数theoretical number理论数treatment处理treatment factor处理因素treatment of date数据处理two-factor analysis of variance双因素方差分析two-sided test双侧检验two-tailed test双尾检验type I error第一类误差type II error第二类误差typical survey典型调查