A sample study is mostly done A. to establish causality in a controlled environment B. to learn how different parameters in the population behave together. C. to rule out any spurious correlation in the data. D. to estimate the parameters of the population.

Who is better at multi-tasking? in business, employees are often asked to perform a complex task when their atten-tion is divided (i.e., multi-tasking). human factors (may 2014) published a study designed to determine whether video game players are better than non–video game play-ers at multi-tasking. each in a sample of 60 college stu-dents was classified as a video game player or a non-player. participants entered a street crossing simulator and were asked to cross a busy street at an unsigned intersec-tion. the simulator was designed to have cars traveling at various high rates of speed in both directions. during the crossing, the students also performed a memory task as a distraction. two variables were measured for each student: (1) a street crossing performance score (measured out of 100 points) and (2) a memory task score (measured out of 20 points). the researchers found no differences in either the street crossing performance or memory task score of video game players and non-gamers. “these results,” say the researchers, “suggest that action video game players [and non-gamers] are equally susceptible to the costs of dividing attention in a complex task”

The purpose of safety stock is to: a. eliminate the possibility of a stockout. b. control the likelihood of a stockout due to variable demand and/or lead time. c. eliminate the likelihood of a stockout due to erroneous inventory tally. d. protect the firm from a sudden decrease in demand. e. replace failed units with good ones.

Chang corp. has $375,000 of assets, and it uses only common equity capital (zero debt). its sales for the last year were $595,000, and its net income was $25,000. stockholders recently voted in a new management team that has promised to lower costs and get the return on equity up to 15.0%. what profit margin would the firm need in order to achieve the 15% roe, holding everything else constant? a. 9.45%b. 9.93%c. 10.42%d. 10.94%e. 11.49%