Official Guide Explanation:
Problem Solving #129




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Solution and Metadata

Question: 129
Page: 78
Difficulty: 5 (Moderate)
Category 1: Arithmetic > Descriptive Statistics > Average
Category 2: Arithmetic > Fractions >

Explanation: If the average sales total for the first eleven months of the year was x, then the sales total for December was 4x. The sales total for the first eleven months, added together, is 11x, so the sales total for the entire year is 11x + 4x = 15x. Thus, the answer to the question is a fraction: ((Dec)/(Year)) = ((4x)/(15x)) = (4/15), choice (B).

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