ASQ Certified Six Sigma Black Belt (CSSBB) — Question 2

What is the Ppk of a process with a spread of 24 units, an average of 68, an upper limit of 82 and a lower limit of 54?

Answer options

Correct answer: C

Explanation

The Ppk is calculated using the formula Ppk = min((USL - mean) / (3 * sigma), (mean - LSL) / (3 * sigma)). In this case, the spread and average values lead to a Ppk of 4.00, which is the lowest of the two calculated values based on the control limits. The other options do not match this calculation and are therefore incorrect.