Exam 2: Graphical and Tabular Descriptive Techniques

It is typical that when taking an exam, few students hand in their exams early; most prefer to reread their papers and hand them in near the end of the scheduled exam period. Under this scenario, a histogram of exam taking times is ____________________ skewed.

One of the variables used to help predict unemployment rates is the rate of inflation. Accordingly, we identify rate of inflation as the ____________________ variable, and unemployment rate as the ____________________ variable.

Electronics Company At a meeting of regional offices managers of a national electronics company, a survey was taken to determine the number of employees the regional managers supervise in the operation of their departments. The results of the survey are shown below. {Electronics Company Narrative} What is the cumulative relative frequency corresponding to 5 employees?

The sum of relative frequencies in a distribution always equals 1.

When one variable increases and the other decreases, we say that there is a(n)____________________ relationship between these two variables.

A relative frequency distribution lists the categories and their counts.

What does the length of each line of a stem-and-leaf display represent?

Correlation implies causation.

Can a scatter diagram be used to explore the relationship between two nominal variables? Explain why or why not.

If when one variable increases the other one also increases, we say that there is a(n)____________________ relationship between these two variables.

Nominal data are also called qualitative or categorical data.

What kind(s)of data can be depicted by a line chart?

In a histogram, each observation is assigned to one or more classes.

Explain the difference between ordinal data and interval data.

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

{Test Grades Narrative} Construct a cumulative frequency and a cumulative relative frequency distribution for this data. What proportion of the exam scores are less than 60? What proportion of the exam scores are 70 or more?

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.).

When two variables are linearly related, and tend to move in opposite directions, we describe the nature of their association as a negative linear relationship.

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