2014 Chapter 2

Question 1

Bar Graph (bar chart)

Answer 1

used to represent the frequencies or relative frequencies for categorical data. It is constructed as follow: (1) On the horizontal axis, provide a label for each category, (2) draw rectangles (bars) of equal width for each category. The height of each rectangle represents the frequency or relative frequency for that category. Ensure that the bars do not touch each other

Question 2

Frequency (count)

Answer 2

The number of observations in each category.

Question 3

Frequency distribution (for a qualitative variable)

Answer 3

A listing of all values that the variable can take and the frequencies for each value.

Question 4

Pareto chart

Answer 4

A bar graph in which the rectangles are presented in decreasing order from left to right

Question 5

Pie chart

Answer 5

Used for categorical data, a pie chart is a circle, divided into sections ( that is, slices or wedges), with each section representing a particular category. The size of the section is proportional to the relative frequency of the category.

Question 6

Relative frequency (for a qualitative variable)

Answer 6

The frequency of a class or category, divided by the sample size.

Question 7

Relative frequency distribution (for a qualitative variable)

Answer 7

A listing of all values that the variable can take and the relative frequencies for each value.

Question 8

Class

Answer 8

A range of data values used to group the elements in a data set.

Question 9

Class limit (lower)

Answer 9

The smallest value within that class.

Question 10

Class limit (upper)

Answer 10

The largest value within that class.

Question 11

Class midpoint

Answer 11

Average of two consecutive lower class limits.

Question 12

Class width

Answer 12

The difference between the lower class limits of two successive classes.

Question 13

Dotplot

Answer 13

A simple graph in which each data point is represented by a dot above the number line. When the sample size is large, each dot may represent more than one data point.

Question 14

Frequency distribution (for quantitative data)

Answer 14

A listing of the frequencies for a set of classes for a quantitative variable. Constructed as follows: (1) determine how many classes you will use, (2) determine the class widths, and (3) determine the upper and lower class limits, so that all classes are non-overlapping.

Question 15

Frequency polygon

Answer 15

Constructed as follows: (1) for each class, plot a point at the midpoint, at a height equal to the frequency for that class, and (2) join each consecutive pair of points with a line segment.

Question 16

Histogram

Answer 16

Constructed using rectangles for each class of data. The heights of the rectangles represent the frequencies or relative frequencies of the class. The widths of the rectangles are all the same and correspond to the class width of the corresponding frequency distribution. The lower class limits are placed on the horizontal axis(along with the upper class limit of the rightmost class), so that the rectangles are touching each other.

Question 17

Relative frequency distribution (quantitative data)

Answer 17

Similar to a frequency distribution except that the relative frequencies instead of the frequencies are provided.

Question 18

Skewed distribution

Answer 18

A right-skewed distribution has a longer tail on the right side than on the left. a left side skewed distribution ahs a longer tail on the left.

Question 19

Stem-and-leaf display

Answer 19

A graphical display for numerical data. The stem unit is ten times the leaf unit, whose value is defined in the display. For each stem, the leaf units are arranged in increasing order.

Question 20

Symmetric

Answer 20

An image is symmetric if there is a line (axis of symmetry) that splits the image in half so that one side is the mirror image of the other.

Question 21

Cumulative frequency distribution

Answer 21

For a discrete variable, shows the total number of observations less than or equal to the category value. For a continuous variable , shows the total number of observations less than or equal to the upper class limit.

Question 22

Cumulative relative frequency distribution

Answer 22

For a discrete variable, shows the proportion of observations less than or equal to the category value. For a continuous variable, shows the proportion of observations less than or equal to the upper class limit.

Question 23

Ogive (pronounce “oh jive”)

Answer 23

The graphical equivalent of a cumulative frequency distribution or a cumulative relative frequency distribution. Like a frequency polygon, and ogive consists of a set of plotted points connected by line segments. The x coordinates of these points are the upper class limits; the y coordinates are the cumulative frequencies or cumulative relative frequencies

Question 24

Time series plot (time series graph)

Answer 24

A graph of time series date. The horizontal axis represents time (for example, hours, days, months, years). The values of the time series data are plotted on the vertical axis, and line segments are drawn to connect the points

Question 25

stemplot

Answer 25

give a quick picture of the shape of a distribution, while including the actual values.

Question 26

cluster

Answer 26

one or more groups of observations in a stemplot

Question 27

histogram

Answer 27

a graph of a frequency distribution in which rectangles with bases on the horizontal axis are given widths equal to the class intervals and heights equal to the corresponding frequencies.

Question 28

frequency

Answer 28

the number of individuals in each class

Question 29

class

Answer 29

a range of possible individual values, created to group frequencies in a distribution or histogram.

Question 30

frequency table

Answer 30

a list of all classes and observations of a given sample

Question 31

modes

Answer 31

the most common frequencies in a distribution, identified by a peak in the display of a frequency distribution

Question 32

unimodal

Answer 32

a distribution with only one major peak

Question 33

symmetric

Answer 33

the values in a distribution smaller and larger than the mode are mirror images

Question 34

right skewed

Answer 34

distributions with more values greater than the mode than less then (right -tailed)

Question 35

left skewed

Answer 35

distributions with more values less than the mode than greater than (left-tailed)

Question 36

outlier

Answer 36

an individual value that falls outside the overall pattern

Question 37

relative frequency

Answer 37

gives the ratio of the frequency of a given individual or class to the total sample size