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. âCambrian explosionâ refers to the great quantity and diversity of life found in what is called the Cambrian layer of the geologic column. The Cambrian age in the geologic time scale is dated by scientists as being about 530 million years old. What is really interesting is not just what is found in this layer, but what is found in the layers above it, and what is not found in layers under it. The Cambrian layer has virtually every phyla known to man.