A rock climber ascends 18 3/4 feet to the top of a rock ledge. The climber descends 8 1/8 feet and takes a break on a rock outcrop. Write and evaluate
an addition expression to show how much farther the rock climber must
descend to reach the original level.

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