Freudian concepts are still popular among empirically-oriented psychologists

When do we use the t-test (and t-distribution)?

A. When the population standard deviation is known B. When the population standard deviation is not known C. When the sample standard deviation is known D. When the sample standard deviation is not known

Which of the following statements about persons who attempt suicide is TRUE?

A) Many people who attempt suicide fail to receive proper psychotherapeutic intervention afterward. B) Often, people who make a serious suicide attempt do not need psychotherapy to understand the seriousness of their behavior. C) Psychotherapy alone is not often effective in dissuading an individual from attempting another suicidal act. D) Most people who attempt suicide do so while in psychotherapy for substance abuse.