2.1, 2, 3.

Question 1

what is data visualization?

Answer 1

Data visualization is a term often used to describe the use of graphical displays to summarize and present information about a data set.

Question 2

what is frequency distribution?

Answer 2

A frequency distribution is a tabular summary of data showing the number (frequency) of observations in each of several nonoverlapping categories or classes.

Question 3

what does frequency distribution show?

Answer 3

A frequency distribution shows the number (frequency) of observations in each of several nonoverlapping classes

Question 4

how to calculate relative frequency?

Answer 4

Relative frequency of a class= Frequency of the class/n

Question 5

what does relative frequency do?

Answer 5

A relative frequency distribution gives a tabular summary of data showing the relative frequency for each class.

Question 6

what is the main function of percent frequency distribution?

Answer 6

A percent frequency distribution summarizes the percent frequency of the data for each class

Question 7

what is a bar chart?

Answer 7

A bar chart is a graphical display for depicting categorical data summarized in a frequency,
relative frequency, or percent frequency distribution.

Question 8

what is a pie chart?

Answer 8

The pie chart provides another graphical display for presenting relative frequency and
percent frequency distributions for categorical data

Question 9

how to construct pie chart?

Answer 9

To construct a pie chart, we first draw a circle to represent all the data. Then we use the relative frequencies to subdivide the circle
into sectors, or parts, that correspond to the relative frequency for each class

Question 10

The three steps necessary to define the classes for

a frequency distribution with quantitative data are:

Answer 10

1. Determine the number of nonoverlapping classes.
2. Determine the width of each class.
3. Determine the class limits

Question 11

how the number of clasees are formed?

Answer 11

Classes are formed by specifying ranges that will be used to group the data.

Question 12

how to calculate approximate class width?

Answer 12

Approximate class width = Largest data value-Smallest data value/Number of classes

Question 13

how the class limits must be chosen?

Answer 13

Class limits must be chosen so that each data item belongs to one and only one class.

Question 14

whats the difference between lower and upper class limits?

Answer 14

The lower class limit identifies the smallest possible data value assigned to the class. The upper class limit identifies the largest possible data value assigned to the class.

Question 15

what is the class midpoint?

Answer 15

The class midpoint is the value halfway between the lower and upper class limits.

Question 16

what is a dot plot?

Answer 16

A horizontal axis shows the range for the data. Each data value is represented by a dot placed above the axis.

Question 17

what is a histogram? how it is constructed?

Answer 17

A common graphical display of quantitative data is a histogram. This graphical display can be prepared for data previously summarized in either a frequency, relative frequency, or percent frequency distribution. A histogram is constructed by placing the variable of interest on the horizontal axis and the frequency, relative frequency, or percent frequency on the vertical 
axis. The frequency, relative frequency, or percent frequency of each class is shown by drawing a rectangle whose base is determined by the class limits on the horizontal axis and whose height is the corresponding frequency, relative frequency, or percent frequency

Question 18

what is the cumulative frequency distribution?

Answer 18

A variation of the frequency distribution that provides another tabular summary of quantitative data is the cumulative frequency distribution

Question 19

what makes the cumulative frequency different from other displays?

Answer 19

The cumulative frequency distribution uses the number of classes, class widths, and class limits developed for the frequency distribution. However, rather than showing the frequency of each class, the cumulative 
frequency distribution shows the number of data items with values less than or equal to the upper class limit of each class.

Question 20

what is the difference between cumulative relative frequency distribution and cumulative percent frequency distribution?

Answer 20

cumulative relative frequency distribution shows the proportion of data items, and a cumulative percent frequency distribution shows the percentage of data items with values less than or equal to the upper limit of each class

Question 21

how the cumulative relative frequency can be computed?

Answer 21

The cumulative relative frequency distribution can be computed either by summing the relative frequencies in the relative frequency distribution or by dividing the cumulative frequencies by the total number of items.

Question 22

what is stem-and-leaf display?

Answer 22

A stem-and-leaf display is a graphical display used to show simultaneously the rank order and shape of a distribution of data

Question 23

what is leaf and stem?

Answer 23

The numbers to the left of the vertical line form the stem,and each digit to the right of the vertical line is a leaf

Question 24

what are the advatages of stem-and-leaf display?

Answer 24

1. The stem-and-leaf display is easier to construct by hand.
2. Within a class interval, the stem-and-leaf display provides more information than the
   histogram because the stem-and-leaf shows the actual data.