IASSC Certified Lean Six Sigma Black Belt (ICBB) — Question 97

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

To calculate the Z value, use the formula Z = (X - μ) / (σ/√n), where X is the sample mean ($3,200), μ is the population mean ($3,600), σ is the standard deviation ($180), and n is the sample size (42). Plugging in the values, the Z value comes out to be 2.22, which is why B is correct. The other options do not accurately reflect the calculated Z value based on the given data.