In a 911 call center, attendants receive emergency calls that they redirect to the police, fire and ambulance. In some cases, attendants must also coordinate emergency interventions involving several units or departments.
The workstations used by the attendants are normally fully adjustable. Indeed, not only the seat working area, but also the height of the surface on which the keyboard and mouse are placed, as well as the height of the surface on which the screens are placed are adjustable using simple buttons.
The work is normally done in a seated position. However, during a coordination intervention, some agents prefer to work in a standing position, which allows them to better manage the stress inherent in these operations.

Since both men and women of all sizes work in this type of service, calculate the dimensions following for a population ranging from the 1st percentile female to the 99th percentile male, using the Kroemer table.
A. The minimum and maximum height of the seat for working in a seated position.
B. The minimum and maximum height of the surface on which the keyboard and mouse are placed. The keyboard has a
2.3 cm thick and the worktop is 2.5 cm thick.(in a standing position and in a seated position)
C. The minimum and maximum height of the surface on which the screens are placed, considering that the information
relevant (the main visual target) is located at a height of 24 cm from the base of the screens, and that they are
located at an average horizontal distance of 65 cm from the eyes of the agents.(in a standing position and in a seated position)