An event can include more than one elementary outcome. Addition rule states that for mutually exclusive events, the probability that one or the other is realized equals the sum of the probabilities of the separate events. The Multiplication rule states that whenever two events are independent, the probability of their joint realization is the product of the probabilities of their being realized separately. Births are mutually exclusive, so probabilities may be combined by the addition rule. Homozygous individuals have two copies of one of the alleles.
Heterozygous individuals have one copy of each allele.
Parameters and Estimates Parameters are quantities used to describe entire populations. Can make an estimate , based upon a sample, rather than using the entire population. P-hat is used to estimate p, when we cannot sample every individual in a population. Another way of presenting standard errors as a range. Confidence interval expresses the level of confidence that the true value of a parameter lies within some specified interval.