Electricity usage. Electricity usage is based on variables including time, season (summer rates can be higher than winter rates due to higher energy demand), and location.

Energy use varies according to the type of industry, the requirements, and area of commercial properties.

In a month, retail malls have an average usage of 23 kWh/

square foot while warehouses have an average usage of 9 kWh/square foot. Assume that both usage amounts of electricity per square foot are normally distributed with standard deviations of 11 and 1.5 kWh/square foot, respectively. If the monthly record of a mall states its electricity usage as 30 kWh/

square foot and a warehouse record states a 10 kWh/square foot, compare these two industries’ usage of electricity using z-values. Which one has a higher relative usage? Explain.