A researcher is performing crosses on mice. When he crosses mice that are heterozygous for a wild-type agouti allele and a dominant mutant yellow allele he observes a total of 102 yellow and 48 agouti in the subsequent generation. He suspects the yellow allele may be lethal in the homozygous dominant state. To test this hypothesis, he performs chi-square tests of both a standard monohybrid 3:1 ratio and a 2:1 ratio that would result from the lethal allele.

Another researcher is performing dihybrid crosses on mice. For a particular trait, he obtains three phenotypes in the F2 generation and suspects either dominant or recessive epistasis is involved. Using a p-value of 0.05, what critical value would he use to compare his calculated chi-value against in these cases?