BelAir has submitted a request for proposal to a number of vendors. It must now evaluate the proposals it has received. Which of the following methods can it use to compare the different systems? a. systems benchmarking
b. data modeling
c. alpha testing
d. beta testing
e. prototyping

Feedback systems do not always involve negative feedback. economic inflation, which is evidenced by continually rising prices, is a positive feedback system. a positive feedback control system, as shown on the right, adds the feedback signal to the input signal, and the resulting signal is used as the input to the process. a simple model of the price-wage inflationary spiral is shown on the right. add additional feedback loops, such as legislative control or control of the tax rate, to stabilize the system. it is assumed that an increase in workers’ salaries, after some time delay, results an increase in prices. under what conditions could prices be stabilized by falsifying or delaying the availability of cost-ofliving data? how would a national wage and price economic guideline program affect the feedback system?