A Recent Paper Described an Experiment in Which 72 Students

question 12

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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Definitions:

Species

A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding to produce fertile offspring.

Arachnida

A class of joint-legged invertebrate animals in the arthropod phylum, including spiders, scorpions, ticks, and mites.

Insecta

The class of arthropods that includes insects, characterized by a three-part body, compound eyes, antennae, and, typically, two pairs of wings.

Exoskeleton

An external skeleton, such as the shell of mollusks or outer covering of arthropods; provides protection and sites of attachment for muscles. Compare with endoskeleton.