I was recently interviewed for an SAP consultant position and one of the interview questions was a short case study asking for an estimate on the total annual sales of air conditioning units in the US. I was given 3 minutes to come up with a number using only a calculator, a pencil, and a paper. What are some ways that this question can be answered?
Use an air conditioner to person ratio. Say that there is one air conditioner per four people in the US. The population is 330 million. That equates to 82.5 million air conditioners. If the average air conditioner lasts nine years then the annual sales would be about 9 million air conditioners.