What are the degrees of freedom for a study with two correlated groups and 10 participants per

Which model of abnormality views abnormal behavior as the result of illogical thinking?

a) psychoanalytic b) cognitive c) behavioral d) biological

A researcher has collected nationwide data for the age of mothers at the time they give birth and the incidence of Down syndrome. What relationship between maternal age and Down syndrome is this researcher likely to find?

a. a very weak relationship b. incidence of Down syndrome increases among those born to mothers who are older c. incidence of Down syndrome decreases among those born to mothers who are older d. incidence of Down syndrome increases among mothers under the age 35