A Bank Is Trying to Determine Which Model of Safe

question 131

Multiple Choice

A bank is trying to determine which model of safe to install. The bank manager believes that each model is equally resistant to safe crackers but sets up a test to be sure. He hires nine safe experts to break into each of the models, timing each endeavor. The results (in seconds) are given next, paired by expert. Let D be the difference: Time to break Safe 1 minus Time to break Safe 2. Which of the following hypotheses will determine if the two safes take, on average, the same amount of time to crack?

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

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Definitions:

Machining Department

A specific division within a manufacturing facility where machinery is used to process materials into finished products.

Manufacturing Overhead

All indirect costs associated with the production process of a company, such as utilities, depreciation, and salaries for management.

Predetermined Overhead Rate

An estimated rate used to allocate manufacturing overhead costs to products based on a particular activity base, such as labor hours or machine hours.

Finishing Department

The division within a manufacturing process where products undergo final touch-ups, quality checks, and preparations before delivery or sale.