ON THIS PAGE T-test functions are used for statistical examination of two population means. A two-sample t-test examines whether two samples are different and is commonly used when two normal distributions have unknown variances and when an experiment uses a small sample size.
In the following sections, the t-test statistical test functions are grouped according to the sample student test that applies to each type of function.
Use the drop-down on each function to see a brief description and the syntax of each function. Click the function name in the syntax description for further details.
Creating a typical t-test report
Two independent samples t-tests
The following functions apply to two independent samples student's t-tests:
ttest_conf
TTest_conf returns the aggregated t-test confidence interval value for two independent samples.
ttest_conf )
ttest_df
TTest_df() returns the aggregated student's t-test value (degrees of freedom)
for two independent series of values.
ttest_df )
ttest_dif
TTest_dif() is a numeric function that returns the aggregated student's t-test mean difference for two independent series of values.
ttest_dif )
ttest_lower
TTest_lower() returns the aggregated value for the lower end of the confidence interval
for two independent series of values.
ttest_lower )
ttest_sig
TTest_sig() returns the aggregated student's t-test 2-tailed level of significance for two independent series of values.
ttest_sig )
ttest_sterr
TTest_sterr() returns the aggregated student's t-test standard error of the mean difference for two independent series of values.
ttest_sterr )
ttest_t
TTest_t() returns the aggregated t value for two independent series of values.
ttest_t )
ttest_upper
TTest_upper() returns the aggregated value for the upper end of the confidence interval
for two independent series of values.
ttest_upper )
Two independent weighted samples t-tests
The following functions to two independent samples student's t-tests where the input data series is given in weighted two-column format:
ttestw_conf
TTestw_conf() returns the aggregated t value for two independent series of values.
ttestw_conf )
ttestw_df
TTestw_df() returns the aggregated student's t-test df value (degrees of freedom) for two independent series of values.
ttestw_df )
ttestw_dif
TTestw_dif() returns the aggregated student's t-test mean difference for two independent
series of values.
ttestw_dif )
ttestw_lower
TTestw_lower() returns the aggregated value for the lower end of the confidence interval for two independent series of values.
ttestw_lower )
ttestw_sig
TTestw_sig() returns the aggregated student's t-test 2-tailed level of significance
for two independent series of values.
ttestw_sig )
ttestw_sterr
TTestw_sterr() returns the aggregated student's t-test standard error of the mean difference
for two independent series of values.
ttestw_sterr )
ttestw_t
TTestw_t() returns the aggregated t value for two independent series of values.
ttestw_t )
ttestw_upper
TTestw_upper() returns the aggregated value for the upper end of the confidence interval
for two independent series of values.
ttestw_upper )
One sample t-tests
The following functions apply to one-sample student's t-tests:
ttest1_conf
TTest1_conf() returns the aggregated confidence interval value for a series of values.
ttest1_conf )
ttest1_df
TTest1_df() returns the aggregated student's t-test df value (degrees of freedom)
for a series of values.
ttest1_df )
ttest1_dif
TTest1_dif() returns the aggregated student's t-test mean difference for a series of values.
ttest1_dif )
ttest1_lower
TTest1_lower() returns the aggregated value for the lower end of the confidence interval for a series of values.
ttest1_lower )
ttest1_sig
TTest1_sig() returns the aggregated student's t-test 2-tailed level of significance
for a series of values.
ttest1_sig )
ttest1_sterr
TTest1_sterr() returns the aggregated student's t-test standard error of the mean difference for a series of values.
ttest1_sterr )
ttest1_t
TTest1_t() returns the aggregated t value for a series of values.
ttest1_t )
ttest1_upper
TTest1_upper() returns the aggregated value for the upper end of the confidence interval for a series of values.
ttest1_upper )
One weighted sample t-tests
The following functions apply to one-sample student's t-tests where the input data series is given in weighted two-column format:
ttest1w_conf
TTest1w_conf() is a numeric function that returns the aggregated confidence interval value for a series of values.
ttest1w_conf )
ttest1w_df
TTest1w_df() returns the aggregated student's t-test df value (degrees of freedom)
for a series of values.
ttest1w_df )
ttest1w_dif
TTest1w_dif() returns the aggregated student's t-test mean difference for a series of values.
ttest1w_dif )
ttest1w_lower
TTest1w_lower() returns the aggregated value for the lower end of the confidence interval for a series of values.
ttest1w_lower )
ttest1w_sig
TTest1w_sig() returns the aggregated student's t-test 2-tailed level of significance
for a series of values.
ttest1w_sig )
ttest1w_sterr
TTest1w_sterr() returns the aggregated student's t-test standard error of the mean difference for a series of values.
ttest1w_sterr )
ttest1w_t
TTest1w_t() returns the aggregated t value for a series of values.
ttest1w_t )
ttest1w_upper
TTest1w_upper() returns the aggregated value for the upper end of the confidence interval
for a series of values.
ttest1w_upper )
