A commercial 3D printer is purchased for $320,000. The salvage value of the printer decreases by 45% each year that it is held. The cost to operate and maintain the machine the first year it is used is $11,500; these costs increase by $4,000 each year. What is the optimal replacement interval and minimum EUAC for the printer, assuming a MARR of 14% is used

Security a has a higher standard deviation of returns than security b. we would expect that: (i) security a would have a risk premium equal to security b. (ii) the likely range of returns for security a in any given year would be higher than the likely range of returns for security b. (iii) the sharpe ratio of a will be higher than the sharpe ratio of b. (a) i only (b) i and ii only (c) ii and iii only (d) i, ii and iii

Reliability and validity reliability and validity are two important considerations that must be made with any type of data collection. reliability refers to the ability to consistently produce a given result. in the context of psychological research, this would mean that any instruments or tools used to collect data do so in consistent, reproducible ways. unfortunately, being consistent in measurement does not necessarily mean that you have measured something correctly. to illustrate this concept, consider a kitchen scale that would be used to measure the weight of cereal that you eat in the morning. if the scale is not properly calibrated, it may consistently under- or overestimate the amount of cereal that’s being measured. while the scale is highly reliable in producing consistent results (e.g., the same amount of cereal poured onto the scale produces the same reading each time), those results are incorrect. this is where validity comes into play. validity refers to the extent to which a given instrument or tool accurately measures what it’s supposed to measure. while any valid measure is by necessity reliable, the reverse is not necessarily true. researchers strive to use instruments that are both highly reliable and valid.

Before the tools that have come from computational psychiatry are ready to be used in everyday practice by psychiatrics, what is needed