Chapter 11, Problem 3RQ

Define environmental variance.

Identify a possible advantage and a possible disadvantage of a genetic test that would identify genes in individuals that increase their probability of having Alzheimer’s disease later in life.

For most cases, a p value of 0.05 is used to determine whether results fit expected values. Is this a magic number, or could p values be set more stringently, say 0.01, or more lax, say 0.10? What effect would these values have on the reliability of the chi-square test?