A Traffic Engineer Plans to Estimate the Average Number of Cars

question 109

Multiple Choice

A traffic engineer plans to estimate the average number of cars that pass through an intersection each day. Based on previous studies the standard deviation is believed to be 52 cars. She wants to estimate the mean to within ±10 cars with 90 percent confidence. The needed sample size for n is:

• A) n = 104 days.
• B) n = 74 days.
• C) n = 10 days.
• D) n = 9 days.

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Definitions:

Decision Processes

The series of steps or stages involved in making a choice or selecting an alternative.

Behavioral Economists

Researchers and practitioners in the field of behavioral economics who study how the psychological and social factors affect individuals' economic decisions.

Tiramisu

An Italian dessert featuring layers of coffee-soaked ladyfingers, mascarpone cheese, cocoa, and sometimes liquor.

Neoclassical Assumption

A perspective in economics that assumes individuals have rational preferences, markets are capable of reaching equilibrium, and information is symmetrically distributed.