A Student at a Local University Took a Total of 20

question 97

Multiple Choice

A student at a local university took a total of 20 exams during freshman year.The student recorded the exam scores as percentages and created the following stem-and-leaf display.The lower stem contains leaves with the digits 0-4 and the upper stem contains leaves with digits 5-9.In addition to describing the distribution,give a reason to account for the shape of this distribution. Exam Grades 9
9
8
8
7
7
6
6
5 $$\begin{array} { l } 555555678 \\2344 \\5678\\\\9\\\\14\end{array}$$ Key:
9 $|~3$ = 93%

• A)The distribution of exam scores is skewed to the left.Typically,the student scored 94% on exams,and the exam scores are tightly clustered in the 90s.Two exam scores are outliers,when the student scored below 65%.It is possible that the student had a difficult time with one of his or her courses in that year.Regardless of the possible reasons,these two scores were unusual compared to the student's other exam scores.
• B)The distribution of exam scores is skewed to the left.Typically,the student scored 95% on exams,and the exam scores are tightly clustered in the 90s.Two exam scores are outliers,when the student scored below 65%.It is possible that the student had a difficult time with one of his or her courses in that year.Regardless of the possible reasons,these two scores were unusual compared to the student's other exam scores.
• C)The distribution of exam scores is skewed to the right.Typically,the student scored 95% on exams,and the exam scores are tightly clustered in the 90s.Two exam scores are outliers,when the student scored below 65%.It is possible that the student had a difficult time with one of his or her courses in that year.Regardless of the possible reasons,these two scores were unusual compared to the student's other exam scores.
• D)The distribution of exam scores is skewed to the left.Typically,the student scored 95% on exams,and the exam scores are tightly clustered in the upper 80s and lower 90s.Two exam scores are outliers,when the student scored below 65%.It is possible that the student had a difficult time with one of his or her courses in that year.Regardless of the possible reasons,these two scores were unusual compared to the student's other exam scores.
• E)The distribution of exam scores is skewed to the left.Typically,the student scored 95% on exams,and the exam scores are tightly clustered in the 90s.

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Definitions:

Sensory Adaptation

The process by which sensory receptors become less sensitive to constant stimuli, allowing individuals to focus on changes in their environment.

Perceptual Redundancy

The presence of more sensory information than is necessary for the recognition or understanding of an object or concept.

Weber's Law

A principle in psychology that states the smallest change in a stimulus that can be detected is a constant proportion of the original stimulus's intensity.

Volley Principle

Principle addressing limitations of the frequency theory of hearing, stating that a cluster of nerve cells can fire neural impulses in rapid succession, producing a volley of impulses.