ASQ Certified Six Sigma Black Belt (CSSBB) — Question 6

A Belt working in a supply chain environment has to make a decision to change suppliers of critical raw materials for a new product upgrade. The purchasing manager is depending on the Belts effort requiring that the average cost of an internal critical raw material component be less than or equal to $3,600 in order to stay within budget. Using a sample of 42 first article components, a Mean of the new product upgrade price of $3,200 and a Standard Deviation of $180 was estimated. Based on the data provided, the Z value for the data assuming a Normal Distribution is?

Answer options

• A. 1.11
• B. 2.22
• C. 4.30
• D. 5.42

Correct answer: B

Explanation

The Z value is calculated using the formula Z = (X - μ) / (σ/√n), where X is the sample mean, μ is the population mean, σ is the standard deviation, and n is the sample size. Plugging in the values gives Z = (3600 - 3200) / (180/√42), which results in approximately 2.22. The other options do not correctly represent this calculation.