Exam 1: Collecting Data

Use the following to answer the questions below: The USStates dataset, used throughout the textbook, contains information on the 50 U.S. states. A small segment from the dataset is displayed in the following table. -The ________ variable is used to understand or predict values of the ________ variable.

In each situation, indicate whether the method of data collection is biased. -A campus bookstore is holding a drawing to give away five free textbooks (one per student). Students enter the contest by writing their name and contact information on an index card. The index cards were placed in a bowl, thoroughly mixed around, and five cards were selected. Those five students were contacted and received their free textbook.

Use the following to answer the questions below: A recent study investigated the impact of psychological stress on men's judgments of female body size. The men were randomly assigned to one of two groups; one group was assigned to participate in a stressful task while the other group did not take part in the task. Then the men were asked to rate the attractiveness of female bodies varying in size from emaciated to obese. -What are the cases in this study?

Use the following to answer the questions below: A realtor's website provides information on area homes that are for sale, including the following variables: List Price, School District, Size, Style. -What are the cases in the realtor's dataset?

Sampling from a Population -A biased sample is one that does not accurately reflect or represent the population.

Use the following to answer the questions below: Identify whether each of the following scenarios describe a randomized comparative experiment or a matched pairs experiment. -Studies have shown that multi-tasking typically results in lower productivity. However, some people believe that individuals who play video games are better at multi-tasking. To investigate this, 28 video game players were randomly assigned to one of two groups. One group was assigned to play a video game that involved driving a car around a track. The other group was assigned to play the same video game while simultaneously answering unrelated trivia questions over the phone.

Use the following to answer the questions below: The Admissions Office at a small university has developed a new 10-minute video about the university to send to prospective students. Before mass-producing the DVD, they would like to test whether it is more effective than the current video. Suppose that you have 12 high school student volunteers who have agreed to take part in an experiment. The explanatory variable to be studied is the type of video, with two levels OLD and NEW. -Would you describe your study as a randomized comparative experiment, a matched pair experiment, or an observational study? Briefly explain.

Use the following to answer the questions below: A high school senior is collecting data on the colleges in which she is interested, including the following variables: Type of college, Tuition, State, Enrollment, Student-Faculty Ratio, Graduation Rate -Refer to the variables collected by the high school senior looking at colleges. Identify a question we might ask about any one of these individual variables.