Battery life has a strong, negative, linear relationship with temperature. If the least-squares regression line using xx = temperature explains 90% of the variation in battery life, which of the following must be the correlation, rr, between battery life and temperature?

Find the volume of the solid obtained by rotating the region enclosed by the curves y=1x and y=7^-x about the x-axis. (use symbolic notation and fractions where needed.) volume =

Which choice names the hypotenuse of triangle xyz? a. segment yx b. segment yz c. segment ab d. segment zx

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