TD_ZTest Output - Teradata® Database

Database Analytic Functions
Product
Teradata® Database
Release Number
17.10
Published
July 2021
Language
English (United States)
Last Update
2021-07-28
dita:mapPath
Teradata_Vantage™___Advanced_SQL_Engine_Analytic_Functions.withLogo_upload_July2021/wnd1589838592459.ditamap
dita:ditavalPath
Teradata_Vantage™___Advanced_SQL_Engine_Analytic_Functions.withLogo_upload_July2021/ayr1485454803741.ditaval
dita:id
B035-1206
lifecycle
previous
Product Category
Teradata Vantage™

Output Table Schema

Column Data Type Description
sample_column_1 VARCHAR Data for first sample population.
sample_column_2 VARCHAR [Column appears only if you specify SecondSampleColumn.] Data for second sample population.
N1 INTEGER Size of first sample.
N2 INTEGER [Column appears only if you specify SecondSampleColumn.] Size of second sample.
mean1 DOUBLE PRECISION Mean of first sample.
mean2 DOUBLE PRECISION [Column appears only if you specify SecondSampleColumn.] Mean of second sample.
AlternativeHypothesis VARCHAR Hypothesis accepted if null hypothesis is rejected (H 1).
z_score DOUBLE PRECISION Test statistic z score.
Alpha DOUBLE PRECISION alpha (see TD_ZTest Syntax Elements).
CriticalValue DOUBLE PRECISION Critical value calculated using Alpha for test (z_α).
p_value DOUBLE PRECISION Probability associated with Z-test statistic:
  • One-tailed, lower-tailed test:

    P(z < z_score)

    This is the lower-tail probability under normal distribution.

  • One-tailed, upper-tailed test:

    P(z > z_score)

    This is the upper-tail probability under normal distribution.

  • Two-tailed test:

    P(z > z_score) + P(z < z_score)

If p_value < alpha, reject null hypothesis.
Conclusion VARCHAR Z-test result, either 'reject null hypothesis' or 'fail to reject null hypothesis'.

If Conclusion is 'reject null hypothesis', rejection confidence level is 1-alpha.