Two Independent Samples of Sizes 40 and 50 Are Randomly

question 31

Multiple Choice

Two independent samples of sizes 40 and 50 are randomly selected from two populations to test the difference between the population means .Assume the population variances are known.The sampling distribution of the sample mean difference is:

• A) normally distributed.
• B) approximately normal.
• C) Student t-distributed with 88 degrees of freedom.
• D) None of these choices.

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Definitions:

Longitudinal Personality Development Studies

Research studies that follow the same individuals over a period of time to observe changes in their personality.

Cohort Effect

The tendency for a research finding to be limited to one group, or cohort, of people, such as people all living during a particular era or in a particular location.

Attrition

The reduction in the number of participants or subjects in a study due to dropouts or failure to follow up.

Cross-Sectional Study

A study of personality development in which people of different ages are assessed at the same time.