A contractor mixes concrete from bags of pre - mix for small jobs How many bags with 7% cement should he mix with 4 bags of 17% cement to produce a mix containing 11% cement ? A ) bags D) 15 bags B) 10 bags C ) 6 bags SHOW WORK
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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