Question

A cell phone service firm is concerned about customer call waiting time at its call center. It is known that the average waiting time is 99.67 (sec) with a standard deviation of 12.24 (sec). Based on the customer survey, they target the customer wait time to be less than 125.00 (sec). Compute the Cpk index for the customer waiting time at this call center (Round to 2 decimal places).

Answer 1

The Cpk index for customer waiting time at the call center is 0.82.

Step-by-step explanation:

To compute the Cpk index for customer waiting time, we need to use the formula:

Cpk = (USL - μ) / 3σ

Where:

• USL is the upper specification limit, which is 125 seconds in this case.
• μ is the average waiting time, which is 99.67 seconds.
• σ is the standard deviation, which is 12.24 seconds.

Substituting these values into the formula:

Cpk = (125 - 99.67) / (3 * 12.24)

Calculating the Cpk:

Cpk = 0.823

Therefore, the Cpk index for the customer waiting time at this call center is 0.82.