Lean Six Sigma Green Belt – Green Belt Exam 2025 – Complete Solutions and Explanations

What is the Mean, Mode & Median for the data in Column 1, Data Set A?

a. Mean = 8.7, Mode = 8, Median = 7

b. Mean = 8.7, Mode = 7, Median = 8

c. Mean = 8, Mode = 8.7, Median = 7

d. Mean = 7, Mode = 7, Median = 8.7

e. Mean = 8, Mode = 8, Median = 7 - CORRECT - Answer B

Formula:

Mean = Sum(x)/n = 8.7

Mode = Most frequent value = 7

Median = because sample is even (n=50), the median is the average of the (n/2)th and

((n/2)+1)th values in the sorted series = 8

Please reference Quantifying Process Variability for more information.

A call center was experiencing customer complaints about time-on-hold and an improvement

team was formed to solve the problem. The manager of the call center joined the team's first

meeting and informed the team that their project would be short-lived because the obvious

solution to the time-on-hold problem was to add more phone lines. With this advice as a basis,

the team crafted a problem statement: "Additional phone lines are needed in order to reduce

the average customer time-on-hold from 6.2 minutes to our target of 45 seconds".

Which of the following best describes the problem statement?