Makeup Directions: Choose the best answer.
1. Which of the following checks are NOT made when constructing a confidence interval for
the difference of two means in an observational study.
a. Both samples are random selections from the population.
b. Both Populations are at least ten times bigger than the samples.
c. Both the expected number of successes and expected number of failures are
least 10
d. Both the samples are at least 30.

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