Bstat ch 2

A relative frequency distribution for quantitative data identifies the

proportion of observations that occur in each class

With respect to a bar chart, which of the following statements is MOST accurate?

A bar chart is a useful tool for qualitative data

relative frequency distribution

A frequency distribution that shows the fraction (proportion) of observations in each category of qualitative data or class of quantitative data

How does an ogive differ from a polygon?

An Ogive is a graph of cumulative (relative) frequency distribution while a Polygon is a graph of a (relative) frequency distribution.

In descriptive statistics, a polygon is best described as a

Graph that connects the midpoints of each class and its associated frequency or relative frequency

There are several guideline to follow when constructing graphs that summarize statistical data. Which of the following statements is LEAST accurate?

Graphs should have a lot of adornments. (Graphs should generally be free of adornments because they often distract from the important data)

What graphical tool is best used to display the relative frequency of grouped, quantitative data?

Histogram Pg. 31

Scatterplot

Is a graphical tool that helps in determining whether or not two quantitative variables are related is some systematic way. Each point in the diagram represents a pair of observed values of the two variables.

Stem-and-leaf diagrams can be used to

Observe individual data points, determine how dispersed the data are, and analyze the shape of the data

Histograms can be used for all of the following except:

Observe individual data points. Note: The actual data points are not observed in a histogram. Their ACTUAL uses: 1. Observe the spread or the variability of the data. 2. Determine the shape of the data. 3. Observe where the data tends to cluster. Pg. 31

When constructing a histogram, what values/labels go on the horizontal (x) axis and the vertical (y) axis?

Quantitative class limits on the horizontal axis; frequency or relative frequency on the vertical axis.

Which of the following statements is least accurate?

The height of each rectangle represents cumulative frequency or cumulative relative frequency

In a given cumulative frequency distribution, the "cumulative frequency" column value for the third class represents

The sum of observations in the first, second, and third classes

Which of the following graphical depictions is useful for observing the spread of the data for a single variable

histogram

One method of graphical presentation for qualitative data is a

pie chart; bar chart

A cumulative relative frequency distribution for quantitative data identifies the

proportion of observations that fall below the upper limit of each class