Alex is constructing a square in which two of its vertices are points x and y. he has already used his straightedge and compass to construct the lines and arcs shown. what should alex do for his next step? a. use a straightedge to draw a horizontal line that contains point z. b. place the point of the compass on point x and draw any arc above it. c. use a straightedge to draw xz¯¯¯¯¯ . d. place the point of the compass on point y and draw an arc that intersects yz¯¯¯¯¯ , using xy as the width of the opening of the compass.

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