Statistics Definition Chapter 2

Front 1

what is a frequency distribution?

Back 1

a tabular summary of data showing the frequency or number of items in each of several non overlapping classes.the objective is to provide insight about the data that cannot be quickly obtained by looking only at the original data.

Front 2

what is relative frequency distribution?

Back 2

the relative frequency of a post is the fraction or the proportion of the total number of data items belonging to the class. it is a tabular summary of a set of data showing the relative frequency of each class.

Front 3

what is percent frequency distribution?

Back 3

the percentage of a class is a relative frequency multiplied by 100. a percent frequency distribution is a tabular summary of a data set showing the percent frequency for each class.

Front 4

what is the definition of a bar chart?

Back 4

a graphical device for depicting qualitative data. One axis usually the horizontal axis we specify the labels that are used for each of the classes.

Front 5

what is the definition of a pareto diagram?

Back 5

In quality control bar charts are used to identify the most important causes of problems. when the bars are arranged in descending order of height from left to right with the most frequently occurring cause appearing first.

Front 6

what is the definition of a pie chart?

Back 6

the pie chart is commonly used graphical device for presenting relative frequency and percent frequency distributions for categorical data. first draw a circle then use the relative frequency to subdivide the circles in sectors that correspond to the relative frequency for each class.

Front 7

what are the 3 steps necessary for defining the class for a frequency distribution with quantitative data?

Back 7

determine the number of non overlapping classes, the width of each class and the class limits

Front 8

what are the guides for determining the number of classes?

Back 8

use between 5-20 classes, data sets with a larger number of elements usually require a larger number of classes, small data sets usually require fewer classes, the goal is to use enough classes to show the variation in the data but not so many classes that some contain only a few data items.

Front 9

what is the guidelines for determining the width of each class?

Back 9

use class of equal width, approximate class width =largest data value-smallest data value/number of classes
making the classes the same width reduces the chance of inappropriate interpretation

Front 10

what is the guidelines for determining the class limits?

Back 10

class limits must be chosen so that each data item belongs to 1 and only 1 class, the lower class limit identifies the smallest possible data value assigned to the class, the appropriate values for the class limits depend on the level of accuracy of data.

Front 11

what is the definition of cumulative distribution?

Back 11

cumulative frequency distribution shows the number of items with values less than or equal to the upper limit of each class.

Front 12

what is the definitions of cumulative relative frequency distribution?

Back 12

this shows the proportion of items with values less than or equal to the upper limit of each class.

Front 13

what is the definition of cumulative percentage frequency distribution?

Back 13

this shows the percentage of items with values less than or equal to the upper limit of each class. The last entry in a cumulative relative frequency distribution always equals the total number of observation.