Clean and Shiny, LLC, Provides Window Cleaning Services to a Number

Essay

Clean and Shiny, LLC, provides window cleaning services to a number of commercial clients. Window-washing crews are given standard times for servicing certain buildings. Given the experience of the crew, these standards can allow more or less time. The Sunshine Crew has recently begun work for Clean and Shiny. Its performance is evaluated using a rolling or moving average standard that reflects the crew's rate of improvement. The table below contains the required time for washing the windows at the home office of the Pony Express National Bank for six months.
Required:
Using three months as the basis for a lean accounting elapsed time metric, compute the average time the Sunshine Crew requires to complete the Pony Express National Bank job over time. Use the first three months as your baseline, then add one new observation and delete one to produce successive averages.