The test statistic is calculated to be z = (28.5 - 30)/(8/sqrt(100)) = -1.5/0.8 = -1.875. The P-value for this statistic is Decision theory is also concerned with a second error possible in significance testing, known as Type II error.o achieve a significance level of 0.05 for a two-sided test, the absolute value of the test statistic (| z |) must be greater than or equal to the critical value 1.96 (which corresponds to the level 0.025 for a one-sided test).
The Cambrian explosion, or less commonly Cambrian radiation, was the relatively short evolutionary event, beginning around 542 million years ago in the Cambrian Period, during which most major animal phyla appeared, as indicated by the fossil record.he Cambrian explosion has generated extensive scientific debate. The seemingly rapid appearance of fossils in the âPrimordial Strataâ was noted as early as the 1840s, and in 1859 Charles Darwin discussed it as one of the main objections that could be made against the theory of evolution by natural selection.
Cambrian Explosion A relatively brief time in geologic history (30-50 MY) when large, hard-bodied forms of animals with most of the major body plans known today appeared in the fossil record. This burst of evolutionary change occurred about 535-525 million years ago. No new major phyla since.