In a comparison of the strengths of concrete produced by four experimental mixes, three specimens were prepared from each type of mix. Each of the 12 specimens was subjected to increasingly compressive loads until breakdown. The accompanying table gives the compressive loads, in tons per square inch, attained at breakdown. Specimen numbers 1-12 are indicated in parentheses for identification purposes.
Mix A
Mix B
Міх с
Mix D
1)
(1) 2.30 (2) 2.30 (3) 2.15 (4) 2.25
4
(5) 2.20 (6) 2.10 (7) 2.05 8 (8) 2.25
(9) 2.35 (10) 2.20 (11) 2.20 (12) 2.25

Calculate the test statistic. (Round your answer to two decimal places.)

State the rejection region. (If the test is one-tailed, enter NONE for the unused region. Round your answers to two decimal places.)