A Tutor Promises to Improve GMAT Scores of Students by More

question 17

Multiple Choice

A tutor promises to improve GMAT scores of students by more than 50 points after three lessons. To see if this is true, the tutor takes a sample of 49 students' test scores after and before they received tutoring. The mean difference was 53 points better after tutoring, with a standard deviation of the difference equal to 12 points. Let µ_D denote the mean of the difference: score after tutoring minus score before tutoring. Which of the following is the appropriate conclusion at the 5% significance level?

• A) Reject H₀; we can conclude that the mean difference in test scores after and before tutoring is greater than 50 points.
• B) Reject H₀; we cannot conclude that the mean difference in test scores after and before tutoring is greater than 50 points.
• C) Fail to reject H₀, we can conclude that the mean difference in test scores after and before tutoring is greater than 50 points.
• D) Fail to reject H₀; we cannot conclude that the mean difference in test scores after and before tutoring is greater than 50 points.

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Definitions:

Interpersonal Communication

The exchange of information, feelings, and meaning between two or more people through verbal and/or non-verbal methods.

Communication Flows

The way information is transmitted within an organization, including upward, downward, and horizontal communication.

Communication Networks

The structured set of communication channels used within an organization or between individuals.

Chromatics

The science of colors, including their theory, production, and application in art and design.