Will mark i just really need help

Agroup of student volunteers participates in a study designed to assess several behavioral interventions for improving output in a repetitive task. prior to the beginning of the study, all volunteers unknowingly observed, and their output is measured. at the beginning of the study, prior to any intervention, the volunteers perform the same task under the observation of a study administrator, and their overall output increases. which of the following terms describes this phenomenon? a. simpson's paradox b. hawthorne effect are d. novelty effect d. pygmalion effect e. observer-expectancy effect

Acompany makes steel lids that have a diameter of 13 inches. what is the area of each lid? round your answer to the nearest hundredth

Benefit(s) from large economies of scale, in which the costs of goods decrease as output increases. natural monopolles perfect competition