A Recent Paper Described an Experiment in Which 72 Students

Multiple Choice

A recent paper described an experiment in which 72 students at a university were assigned at random to one of two groups. All students took a class from the same instructor in the same semester. Students were required to report to an assigned room at a set time to fill out a course evaluation. One group of students reported to a room where they were offered a small bar of chocolate as they entered. The other group reported to a different room where they were not offered chocolate. Summary statistics for the overall course evaluation score are given in the accompanying table. A 95% confidence interval for the mean difference in overall course evaluation score is:

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B)
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D)
E)