Exam 1: Statistics, Data, and Statistical Thinking

A variable is a characteristic or property of a population.

When we take data obtained from a sample and make generalizations or predictions about the entire population, we are utilizing inferential statistics.

Explain why it is not necessary to provide a measure of reliability when a census is used rather than a sample.

As part of an economics class project, students were asked to randomly select 500 New York Stock Exchange (NYSE) stocks from the Wall Street Journal. As part of the project, students were asked to summarize the current prices (also referred to as the closing price of the stock for a particular trading date) of the collected stocks using graphical and numerical techniques. Identify the population of interest for this study.

A high school guidance counselor analyzed data from a sample of 900 community colleges throughout the United States. One of his goals was to estimate the annual tuition costs of community colleges in the United States. Describe the population and variable of interest to the guidance counselor.

Statistics involves two different processes, describing sets of data and drawing conclusions about the sets of data on the basis of sampling.

A study attempted to estimate the proportion of Florida residents who were willing to spend more tax dollars on protecting the Florida beaches from environmental disasters. Forty-eight hundred Florida residents were surveyed.Which of the following describes the variable of interest in the study?

The manager of a car dealership records the colors of automobiles on a used car lot. Identify the type of data collected.

A student worked on her statistics project in the library and found a reference book that contained the median family incomes for all 50 states. On her project, she would report her data as being collected __________.

An usher records the number of unoccupied seats in a movie theater during each viewing of a film. Identify the type of data collected.

Define statistical thinking.

What is the most common way to satisfy the representative sample requirement?

A postal worker counts the number of complaint letters received by the United States Postal Service in a given day. Identify the type of data collected.

Parking at a large university has become a very big problem. University administrators are interested in determining the average parking time (e.g. the time it takes a student to find a parking spot) of its students. An administrator inconspicuously followed 250 students and carefully recorded their parking times. Identify the population of interest to the university administration.

Gender is one variable of interest in a study of the effectiveness of a new medication. For data entry purposes, the researcher conducting the study assigns 1 for Male and 2 for Female. Is the gender data quantitative or qualitative?

Three female students and two male students are to be chosen from a group of 30 female students and 20 male students. Does this sample of five students satisfy the conditions to be a random sample of the 50 students in the group? Explain.

When using data from a published source, it is not important to know how the data were collected and whether randomization was used.

A study in the state of Georgia was conducted to determine the percentage of all community college students who have taken at least one online class. 1500 community college students were contacted and asked if they had taken at least one online class during their time at their community college. These responses were then used to estimate the percentage of all community college students who have taken at least one online class. Identify the population of interest in this study.

Measurement is the process of assigning numbers to variables of individual population units.

A student completing a research project for a criminal justice class obtained a radar gun for determining automobile speeds and recorded the speeds of automobiles passing a fixed location over a period of several hours. The student was unaware that the device needed to be recharged after two hours of use and that the speeds recorded after two hours were not reliable. What type of problem has occurred?