A Tutor Promises to Improve GMAT Scores of Students by More

question 126

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 hypotheses will determine if the students improved their test scores by more than 50 points after being tutored?

• A) H₀: µ_D ≤ 0, H_A: µ_D > 0
• B) H₀: µ_D ≥ 0, H_A: µ_D < 0
• C) H₀: µ_D ≤ 50, H_A: µ_D > 50
• D) H₀: µ_D ≥ 50, H_A: µ_D < 50

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The professional maintenance of a favorable public image by a company, organization, or famous person.

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Financial or material support provided to events, activities, individuals, or organizations, typically for promotional purposes.

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Events where companies within a specific industry showcase and demonstrate their new products and services to potential clients and partners.

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The public visibility or awareness for any product, service, or company that is gained through media attention and coverage.