William arcenio is remodeling his home. in order to save money, he is upgrading the plumbing himself. he needs 18 pieces of copper tubing, each 2/9 of a foot long. if he has a 2-foot piece of tubing, will that be enough? how much more does he need or how much tubing will he have left over?

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