A “frequency distribution table” is a
chart that provides an overview of the
state of data analysis.
Reference
Histogram
Histograms, which express dispersion
through bar graphs, can also be used to
represent the state of data distribution.
Through histograms, information such
as an overview of the data as a whole,
its central position, and the magnitude
of dispersion can be checked.
Basic theory
Data count
Reference
Frequency distribution
table
Chapter 7
(3)Normal distribution
“Normal distribution” allows for data variation to be expressed in chart
form using a convex-shaped graph known as a “bell curve.” Rounded in
the same way as an actual bell, a bell curve is symmetrically balanced to
the left and right with the mean positioned at its center.
In terms of its properties, normal distribution contains data within approximately 68% of the mean plus or minus a standard deviation of 1, approximately 95% of the mean plus or minus a standard deviation of 2, and approximately 99% of the mean plus or minus a standard deviation of 3.
This data can be used to express standard kinds of knowledge such as the
height of a large number of people, the weight of a large quantity of products produced by the same process, or errors in measurement.
Such properties can be utilized to predict the amount of data that differs
greatly from the mean, and in turn the quantity of inferior industrial goods
manufactured.
68%
Standard deviation
Data value
Mean
7-1-3 Theory of information
In order to grasp the fundamental logic behind the numeric values and data
managed by computers, it is necessary to understand various concepts including methods of expressing information quantity, the reasoning behind
digitization, and character representation.
1
Units measuring volume of information
“Bits” and “bytes” are units that are used to measure quantities of information, and represent the memory capacity and performance of a computer. Knowing about these units will also prove helpful in understanding PC
performance and memory, as well as hard disk memory capacity.
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