Briefly explain how resource demands are generated in a probabilistic workload model. If the demand for processor time by transactions is distributed normally with a mean of 5 microseconds and a variance of 2.5 microseconds and the random number generator you use for your workload model is functioning correctly, what percentage of the transactions generated should request more than 7 microseconds of processor time? How could you check that, in fact, this is the case with your workload model? (Hint: You will need to remember material taught to you in your introductory statistics course to be able to answer this question.)

Assume, now, that the amount of processor time demanded by transactions varies considerably throughout the day. Assume, also, that the probabilistic workload model is to be used as input to a simulation model of a hardware/software platform that your organization is considering purchasing. As the manager of internal audit for your organization, how would you recommend that the substantial variations in processor time demanded by transactions throughout the day be taken into account in terms of the design and implementation of the workload model?