Exam 2: Graphical and Tabular Descriptive Techniques

A supermarket's monthly sales (in thousands of dollars) for the last year were as follows: Construct a relative frequency bar chart for this data set. How many observations are there in this data set?

Test Grades: The scores on a calculus test for a random sample of 40 students are as follows: -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?

The original observations cannot be determined once they are grouped into a frequency distribution.

Test Grades: The scores on a calculus test for a random sample of 40 students are as follows: -Construct a relative frequency histogram for this data set and discuss its shape.

Business School Graduates: A sample of business school graduates were asked what their major was. The results are shown in the following frequency distribution. -Draw a pie chart to summarize this data. Which major was the most popular?

A(n) ____________________ is created by plotting the value of the variable on the vertical axis and the time periods on the horizontal axis.

Which of the following statements about histograms is false?

Twenty-five voters participating in a recent election exit poll in Alabama were asked to state their political party affiliation. Coding the data 1 for Republican, 2 for Democrat, and 3 for Independent, the data collected were as follows: 3, 1, 2, 3, 1, 3, 3, 2, 1, 3, 3, 2, 1, 1, 3, 2, 3, 1, 3, 2, 3, 2, 1, 1, 3, 1, 2, 2, 1, and 3. Develop a frequency distribution and a relative frequency distribution for this data. What does the data suggest about the strength of the political parties in Alabama?

When two variables tend to move in opposite directions, yet still form a linear pattern, how do you describe their relationship?

In applications involving two variables, X and Y, where one variable depends to some degree on the other, we call X the ____________________ variable.

A(n) ____________________ distribution lists the categories of a nominal variable and the proportion with which each occurs.

Internet Classes: A survey of 25 students was conducted to determine how they rate the quality of Internet classes. Students were asked to rate the overall quality from 0 (no quality at all) to 100 (extremely good quality). The stem-and-leaf display of the data is shown below. -What percentage of the students rated the overall quality of on-line classes as being below 40?

Test Grades: The scores on a calculus test for a random sample of 40 students are as follows: -Construct a stem-and-leaf display for this data set. Describe the shape of the data.

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. Construct a frequency bar chart and a pie chart from this data. How long did it take most employees to complete the task?

The graph below is an example of a histogram.

The length of each line in a step-and-leaf display represents the ____________________ of that class interval defined by the stems.

Nominal data are also called qualitative or categorical data.

Observations that are taken during successive points in time are called ____________________ data.

A stem-and-leaf display represents nominal data.

The more observations we have, the ____________________ the number of class intervals we need to use to draw a useful histogram.