Todd Takes an Achievement Test That Yields Standard Scores

question 117

Multiple Choice

Todd takes an achievement test that yields standard scores.The mean of the test scores is 200, and the standard deviation is 50.If Todd does better than 84% of the students in his age-group who take the test, his standard score is:

• A)150
• B)200
• C)250
• D)300

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Definitions:

Maximum Parsimony

Maximum parsimony is a statistical method for reconstructing phylogenies that identifies the tree topology that minimizes the total amount of change, or the number of steps, required to fit the data to the tree.

Introgression

Introgression describes the movement of alleles from one species or population to another.

Incomplete Lineage Sorting

Occurs when a genetic polymorphism persists through several speciation events. When fixation of alternative alleles eventually occurs in the descendent species, the pattern of retention of alleles may yield a gene tree that differs from the true phylogeny of the species.

Genetic Hitchhiking

Genetic hitchhiking occurs when an allele increases in frequency because it is physically linked to a positively selected allele at a nearby locus.