A Tutor Promises to Improve GMAT Scores of Students by More

question 11

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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Definitions:

Materials Costs

The expense incurred for raw materials that are transformed into finished products in the manufacturing process.

Equivalent Units

A term in process costing used to convert partially completed units into a number of complete units for costing purposes.

Step-Down Method

An allocation method used in accounting to distribute costs among departments or products, starting with the department that provides the most services to others.

Service Department Costs

Expenses related to departments that support the production process but do not directly engage in manufacturing.