Stat 351

In purchasing a used computer, there are a number of variables to consider. The age of the computer is an example of a(n) ____________________ variable.

interval quantitative numerical

The Chief of Police conducted a survey of the officers on his squad. An officer's shooting score at target practice is an example of a(n) ____________________ variable.

interval quantitative numerical

In purchasing an automobile, there are a number of variables to consider. The body style of the car (sedan, coupe, wagon, etc.) is an example of a(n) ____________________ variable.

nominal categorical qualitative

The Dean of Students conducted a survey on campus. The gender of each student is an example of a(n) ____________________ variable

nominal categorical qualitative

The final grade received in a Literature course (A, B, C, D, or F) is an example of a(n) ____________________ variable.

nominal categorical qualitative

Car buyers were asked to indicate the car dealer they believed offered the best overall service. The four choices were Contour Motors (C), Modern Chrysler (M), Tonneau Auto (T), and Uncanny Chevrolet (U). The following data were obtained: T C C C U C M T C U U M C M T C M M C M T C C T U M M C C T T U C U T M M C U T What percentage of car buyers identified Contour Motors as having the best overall service? a. 1/4 = 0.25 or 25% b. 14/40 = 0.35 or 35% c. 14% d. None of these choices.

B

Suppose you measure the number of minutes it takes an employee to complete a task, where the maximum allowed time is 5 minutes, and each time is rounded to the nearest minute. Data from 130 employees is summarized below. How long did it take most employees to complete the task? Time (minutes) 1 2 3 4 5 Frequency 25 40 50 35 30 a. 5 minutes b. 3 minutes c. 30 minutes d. 50 minutes

B

Which situation identifies when to use pie charts and/or bar charts? a. You want to describe a single set of data. b. Your data is nominal. c. You want to show the number or the percentage of individuals in each category. d. All of these choices are true.

D

Give an example of interval data that can also be treated as ordinal data and nominal data.

Example: Your actual age is interval data; your age group (1-17; 18-24; 25-30; etc.) is ordinal data; and whether or not you are over age 25 is nominal data.

A bar chart is used to represent interval data.

False

A frequency distribution lists the categories and the proportion with which each occurs.

False

A relative frequency distribution lists the categories and their counts.

False

From a pie chart you are able to find the frequency for each category.

False

The values of quantitative data are categories.

False

With nominal data, there is one and only one way the possible values can be ordered.

False

Your age group (1-9; 10-19; 20-29; 30-39; etc.) is an interval variable.

False

Your final grade in a course (A, B, C, D, E) is a nominal variable.

False

The Dean of Students conducted a survey on campus. Class rank (Freshman, Sophomore, Junior, and Senior) is an example of a(n) ____________________ variable.

Ordinal

Provide one example of ordinal data; one example of nominal data; and one example of interval data.

Ordinal data example: Response to a market research survey question measured on the Likert scale using the code: 1 = strongly agree, 2 = agree, 3 = neutral, 4 = disagree, and 5 = strongly disagree. Nominal data example: Voters' political party affiliation for using the code: 1 = Democrat, 2 = Republican, and 3 = Independent. Interval data example: The temperature on a golf course during the U.S. Master's Tournament. (degrees Fahrenheit).

Explain the difference between ordinal data and interval data.

The critical difference between them is that the intervals or differences between values of interval data are consistent and meaningful. That is, we can calculate the difference and interpret the results. Because the codes representing ordinal data are arbitrarily assigned except for the order, we cannot calculate and interpret differences.

Explain why religious preference is not an ordinal variable.

The values of religious preference cannot be ranked in order in any way.

A variable is some characteristic of a population or sample.

True

All calculations are permitted on interval data.

True

Bar and pie charts are graphical techniques for nominal data. The former focus the attention on the frequency of the occurrences of each category, and the later emphasizes the proportion of occurrences of each category.

True

Interval data may be treated as ordinal or nominal.

True

Interval data, such as heights, weights, incomes, and distances, are also referred to as quantitative or numerical data.

True

Nominal data are also called qualitative or categorical.

True

One of the advantages of a pie chart is that it clearly shows that the total percentages of all the categories add to 100%.

True

Whether or not you are over the age of 21 is a nominal variable.

True

You cannot calculate and interpret differences between numbers assigned to ordinal data.

True

Your age is an interval variable.

True

Your gender is a nominal variable

True

At the end of a safari, the tour guide asks the vacationers to respond to the questions listed below. For each question, determine whether the possible responses are interval, nominal, or ordinal. a. How many safaris have you taken prior to this one? b. Do you feel that your tour safari lasted sufficiently long (yes/no)? c. Which of the following features of the accommodations did you find most attractive: location, facilities, room size, service, or price? d. What is the maximum number of hours per day that you would like to spend traveling? e. Is your overall rating of this safari: excellent, good, fair, or poor?

a. Interval b. Nominal c. Nominal d. Interval e. Ordinal

For each of the following, indicate whether the variable of interest is nominal or interval. a. Your marital status. b. Whether you are a U.S. citizen. c. Sally's travel time from her dorm to the student union on campus. d. The amount of time you spent last week on your homework. e. The number of cars parked in a certain parking lot at any given time. f. Kate's favorite brand of sneakers.

a. Nominal b. Nominal c. Interval d. Interval e. Interval f. Nominal

For each of the following examples, identify the data type as nominal, ordinal, or interval. a. The final grade received by a student in a neuro-science class. b. The number of students in a Physics course. c. The starting salary of a PhD graduate. d. The size of an order of fries (small, medium, large, super-size) purchased by a Burger King customer. e. The college you are enrolled in (Arts and Sciences, Business, Education, etc.).

a. Ordinal b. Interval c. Interval d. Ordinal e. Nominal

All calculations are permitted on what type of data? a. Interval data c. Ordinal data b. Nominal data d. All of these choices are true.

a. Interval data

The classification of student major (accounting, economics, management, marketing, other) is an example of a(n) a. nominal random variable. c. continuous random variable. b. interval random variable. d. parameter.

a. nominal random variable

A researcher wishes to estimate the textbook costs of first-year students at Barry University. To do so, he recorded the textbook cost of 300 first-year students and found that their average textbook cost was $195 per semester. The variable of interest to the researcher is a. textbook cost. c. number of students. b. class rank. d. name of university.

a. textbook cost

Which of the following situations is best suited for a pie chart? a. The number of dollars spent this year on each type of legal gambling. b. The percentage of a charitable donation that goes to administrative costs vs. directly to the charity. c. The number of students in your class who received an A, B, C, D, F on their exam. d. All of these choices are true.

b.

Which of the following statements about pie charts is false? a. A pie chart is a graphical representation of a relative frequency distribution. b. You can always determine frequencies for each category by looking at a pie chart. c. The total percentage of all the slices of a pie chart is 100%. d. The area of a slice of a pie chart is the proportion of all the individuals that fall into that particular category.

b.

For what type of data are frequencies the only calculations that can be done? a. Interval data c. Ordinal data b. Nominal data d. None of these choices.

b. Nominal data

For which type of data are the values arbitrary numbers? a. Interval data c. Ordinal data b. Nominal data d. None of these choices.

b.Nominal data

Values must represent ordered rankings for what type of data? a. Interval data c. Ordinal data b. Nominal data d. None of these choices.

c. ordinal date

The classification of student class designation (freshman, sophomore, junior, senior) is an example of a(n) a. nominal random variable. c. ordinal random variable. b. interval random variable. d. a parameter.

c. ordinal random variable