Solve below please (urgent)

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

Find the measure of angle c in the following triangle.

Miguel has 334 baseball cards and 278 football cards. he says, i have 612 cards in all. is that reasonable? explain using the words round and estimate.