# 5ttt Essay A pie chart (or a circle graph) is a circular[->0] chart[->1] divided into sectors[->2], illustrating proportion. In a pie chart, the arc length[->3] of each sector (and consequently its central angle[->4] and area[->5]), is proportional[->6] to the quantity it represents. When angles are measured with 1 turn[->7] as unit then a number of percent is identified with the same number of centiturns. Together, the sectors create a full disk. It is named for its resemblance to a pie[->8] which has been sliced.

A line chart or line graph is a type of graph[->9], which displays information as a series of data points connected by straight line segments. It is a basic type of chart[->10] common in many fields. It is an extension of a scatter graph[->11], and is created by connecting a series of points that represent individual measurements with line segments. A line chart is often used to visualize a trend in data over intervals of time – a time series[->12] – thus the line is often drawn chronologically.

In statistics[->13], a histogram is a graphical representation showing a visual impression of the distribution of data. It is an estimate of the probability distribution[->14] of a continuous variable and was first introduced by Karl Pearson[->15]. A histogram consists of tabular frequencies[->16], shown as adjacent rectangles[->17], erected over discrete intervals (bins), with an area equal to the frequency of the observations in the interval. The height of a rectangle is also equal to the frequency density of the interval, i.e., the frequency divided by the width of the interval. The total area of the histogram is equal to the number of data. A histogram may also be normalized[->18] displaying relative frequencies. It then shows the proportion of cases that fall into each of several categories[->19], with the total area equaling 1. The categories are usually specified as consecutive, non-overlapping intervals[->20] of a variable. The categories (intervals) must be adjacent, and often are chosen to be of the same size.

[->0] - /wiki/Circle
[->1] - /wiki/Chart
[->2] - /wiki/Circular_sector
[->3] - /wiki/Arc_length
[->4] - /wiki/Central_angle
[->5] - /wiki/Area
[->6] - /wiki/Proportionality_(mathematics)
[->7] - /wiki/Turn_(geometry)
[->8] - /wiki/Pie
[->9] - /wiki/Graph_of_a_function
[->10] - /wiki/Chart
[->11] - /wiki/Scatter_graph
[->12] - /wiki/Time_series
[->13] - /wiki/Statistics
[->14] - /wiki/Probability_distribution
[->15] - /wiki/Karl_Pearson
[->16] - /wiki/Frequency_(statistics)
[->17] - /wiki/Rectangle
[->18] - /wiki/Normalization_(statistics)
[->19] - /wiki/Categorization
[->20] - /wiki/Interval_(mathematics)

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