Exam 1: Collecting Data

Use the following to answer the questions below: A high school senior is collecting data on the colleges in which she is interested. Identify the variables as either categorical or quantitative. -Type of college: Private or Public college

Use the following to answer the questions below: A university's Admissions staff sends one of four different representatives to work at college fairs. A study was conducted to evaluate the relative effectiveness of the four representatives. For each college fair over the course of the year, the number of inquiries from students, the type of fair (large or small), the representative who worked at that fair, and the percent of inquiries that resulted in applications were recorded. It was found that one of the representatives was far more effective at getting lots of inquiries. -Is this an observational study or an experiment?

Use the following to answer the questions below: A university's Admissions staff sends one of four different representatives to work at college fairs. A study was conducted to evaluate the relative effectiveness of the four representatives. For each college fair over the course of the year, the number of inquiries from students, the type of fair (large or small), the representative who worked at that fair, and the percent of inquiries that resulted in applications were recorded. It was found that one of the representatives was far more effective at getting lots of inquiries. -What are the variables recorded in this study? List them and identify each as either categorical or quantitative.

Use the following to answer the questions below: State whether the data are best described as a population or a sample. -A researcher has identified a beach with a substantial number of driftwood logs. She randomly chooses 30 logs and takes core samples from those logs.

Use the following to answer the questions below: State whether the data are best described as a population or a sample. -A football fan recorded the number of rushing yards for all NFL running backs who played last season.

Use the following to answer the questions below: A realtor's website provides information on area homes that are for sale. Identify each of the variables as either categorical or quantitative. -List Price: amount, in thousands of dollars, for which the house is being sold

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 -What are the cases in the high school senior's dataset?

Use the following to answer the questions below: A high school senior is collecting data on the colleges in which she is interested. Identify the variables as either categorical or quantitative. -Zip Code: the zip code of the part of the country in which the college is located

Use the following to answer the questions below: A high school senior is collecting data on the colleges in which she is interested. Identify the variables as either categorical or quantitative. -State: the state in which the college is located

Use the following to answer the questions below: A realtor's website provides information on area homes that are for sale. Identify each of the variables as either categorical or quantitative. -Style: the style of home (ranch, Cape Cod, Victorian, etc.)

In each situation, indicate whether the method of data collection is biased. -A professor is considering a new textbook for her introductory statistics class. She wants to choose a book that emphasizes graphing data. A book that she is considering has 530 pages. To estimate the proportion of pages in the book that have displays of data, she randomly generates 20 numbers between 1 and 530. She then records whether or not each selected page contains displays of 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. -What variable was used to determine that 42.7% of Connecticut state residents have a college degree? Is it categorical or quantitative?

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. -Identify the response variable in this experiment.

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. -When purchasing some foods, like Jello, at the grocery store, the color of the product typically "matches" the taste. For example, lemon-flavored Jello is yellow, cherry-flavored Jello is red, orange-flavored Jello is orange, and grape-flavored Jello is purple. But, does the color of our food impact the taste that we perceive? Suppose you want to design an experiment to address this question. Note that you can easily make your own "Jello" with simple ingredients that include unflavored gelatin, flavored extracts, and food coloring. Assume that the 30 college students are willing to participate in your study and the response variable is the number of flavors correctly identified. How would you design a randomized comparative experiment with two groups, each getting a different treatment? Be sure to explain how randomization is used.

In each situation, indicate whether the method of data collection is biased. -Ask the students at the gym on a Tuesday afternoon how many hours a week they work out to estimate the average amount of time students at the university work out.

Use the following to answer the questions below: A group of researchers investigated the effect of media usage (whether or not subjects watch television or use the Internet) in the bedroom on "Tiredness" during the day (measured on a 50 point scale). -Identify the variables as either explanatory or response variables.

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. -Explain what it means, in the context of this study, to want the subjects to be "blind."

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. -What variable from this dataset is displayed? Is it categorical or quantitative?

In elementary school (Grades 1 through 6) there is a strong association between a child's height and reading ability. What is a possible confounding variable that would help explain this relationship? Explain briefly.

Use the following to answer the questions below: A group of researchers investigated the effect of media usage (whether or not subjects watch television or use the Internet) in the bedroom on "Tiredness" during the day (measured on a 50 point scale). -To collect these data, the researchers randomly selected homes to visit and interviewed the adult member of the household whose birthday was nearest. Is this an experiment or an observational study?