# For the test statistic value: STATS_F_TEST(expr1, expr2, 'STATISTIC') : STATS_F_TEST « Linear Regression Functions « Oracle PL/SQL Tutorial

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 Oracle PL/SQL Tutorial » Linear Regression Functions » STATS_F_TEST
20.12.1.For the test statistic value: STATS_F_TEST(expr1, expr2, 'STATISTIC')

This function tests the equality of two population variances.

The resulting f value is the ratio of one sample variance to the other sample variance.

Values very different from 1 usually indicate significant differences between the two variances.

 ```SQL> -- create demo table SQL> create table myTable(   2    id           NUMBER(2),   3    value        NUMBER(6,2)   4  )   5  / Table created. SQL> SQL> -- prepare data SQL> insert into myTable(ID,  value)values (1,9); 1 row created. SQL> insert into myTable(ID,  value)values (2,2.11); 1 row created. SQL> insert into myTable(ID,  value)values (3,3.44); 1 row created. SQL> insert into myTable(ID,  value)values (4,-4.21); 1 row created. SQL> insert into myTable(ID,  value)values (5,10); 1 row created. SQL> insert into myTable(ID,  value)values (6,3); 1 row created. SQL> insert into myTable(ID,  value)values (7,-5.88); 1 row created. SQL> insert into myTable(ID,  value)values (8,123.45); 1 row created. SQL> insert into myTable(ID,  value)values (9,98.23); 1 row created. SQL> insert into myTable(ID,  value)values (10,938.23); 1 row created. SQL> insert into myTable(ID,  value)values (11,984.23); 1 row created. SQL> insert into myTable(ID,  value)values (12,198.23); 1 row created. SQL> insert into myTable(ID,  value)values (13,928.87); 1 row created. SQL> insert into myTable(ID,  value)values (14,25.37); 1 row created. SQL> insert into myTable(ID,  value)values (15,918.3); 1 row created. SQL> insert into myTable(ID,  value)values (16,9.23); 1 row created. SQL> insert into myTable(ID,  value)values (17,8.23); 1 row created. SQL> SQL> select * from myTable   2  /         ID      VALUE ---------- ----------          1          9          2       2.11          3       3.44          4      -4.21          5         10          6          3          7      -5.88          8     123.45          9      98.23         10     938.23         11     984.23         ID      VALUE ---------- ----------         12     198.23         13     928.87         14      25.37         15      918.3         16       9.23         17       8.23 17 rows selected. SQL> SQL> SQL> SELECT STATS_F_TEST(1.2, value, 'STATISTIC') FROM myTable; STATS_F_TEST(1.2,VALUE,'STATISTIC') ----------------------------------- SQL> SQL> SQL> -- clean the table SQL> drop table myTable   2  / Table dropped.```
 20.12.STATS_F_TEST 20.12.1. For the test statistic value: STATS_F_TEST(expr1, expr2, 'STATISTIC') 20.12.2. For degrees of freedom: STATS_F_TEST(expr1, expr2, 'DF_NUM') 20.12.3. STATS_F_TEST(expr1, expr2, 'DF_DEN') 20.12.4. For significance level of one-sided test: STATS_F_TEST(expr1, expr2, 'ONE_SIDED_SIG') 20.12.5. For significance level of two-sided test: STATS_F_TEST(expr1, expr2, 'TWO_SIDED_SIG')