What Is A Frequency Distribution - How To Construct Make A Frequency Distribution Table
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In this video we discuss
In this video we discuss what is a frequency distribution in statistics and how to construct a frequency distribution table.
Transcript/notes
Frequency distributions
A frequency distribution is a process that takes raw, ungrouped data and summarizes it in a table form. It basically gives you a way to organize and describe a data set.
In this frequency distribution, column 1 shows the classes or intervals, and, we will go over how to calculate these in the next video. Column 2 shows a handwritten tally for each of the data points in each of the classes, for example there are 5 data points that lie between 175 and 223. Column 3 shows the frequency for each of the classes, which is actually the written number of the tally from the previous column. And column 4 shows the relative frequency, for each of the classes.
The relative frequency is actually a fraction, and it is calculated by taking the number of data points in a given class and dividing that by the total number of data points in the data set. So, there are 14 data points that are in the 322 to 370 class. There are a total of 90 data points in the set. 14 divided by 90 equals 0.1555. Which is actually a percentage, rounding off, we get 15.6 percent. So the relative frequency shows you the percentage of values that are in each class.
A little note, frequency is usually noted as f, and relative frequency is usually noted as f over n, with n being the total number of data points in the data set.
There are 3 main types of frequency distributions that are often used, a grouped frequency distribution, which is the one we have been looking at, as it has data grouped within classes or intervals. There is also a cumulative frequency distribution, where the classes are less than or equal to an upper class boundary.
An ungrouped frequency distribution has classes with a single data value, and these are used when the range of data values is small. And there is a categorical frequency distribution which is used when data can be placed into specific categories, as you can see here, the classes in this distribution is comprised of months.
In the next video we will cover the class limits, how to calculate how many classes to use, and how to calculate the actual limits or widths of each class.
Timestamps
0:00 What Is A Frequency Distribution?
0:12 Class Limits Column For Frequency Distribution
0:18 Hand Tally Column For Frequency Distribution
0:27 Frequency Column For Frequency Distribution
0:34 Relative Frequency Column For Frequency Distribution
1:21 Types Of Frequency Distributions
Transcript/notes
Frequency distributions
A frequency distribution is a process that takes raw, ungrouped data and summarizes it in a table form. It basically gives you a way to organize and describe a data set.
In this frequency distribution, column 1 shows the classes or intervals, and, we will go over how to calculate these in the next video. Column 2 shows a handwritten tally for each of the data points in each of the classes, for example there are 5 data points that lie between 175 and 223. Column 3 shows the frequency for each of the classes, which is actually the written number of the tally from the previous column. And column 4 shows the relative frequency, for each of the classes.
The relative frequency is actually a fraction, and it is calculated by taking the number of data points in a given class and dividing that by the total number of data points in the data set. So, there are 14 data points that are in the 322 to 370 class. There are a total of 90 data points in the set. 14 divided by 90 equals 0.1555. Which is actually a percentage, rounding off, we get 15.6 percent. So the relative frequency shows you the percentage of values that are in each class.
A little note, frequency is usually noted as f, and relative frequency is usually noted as f over n, with n being the total number of data points in the data set.
There are 3 main types of frequency distributions that are often used, a grouped frequency distribution, which is the one we have been looking at, as it has data grouped within classes or intervals. There is also a cumulative frequency distribution, where the classes are less than or equal to an upper class boundary.
An ungrouped frequency distribution has classes with a single data value, and these are used when the range of data values is small. And there is a categorical frequency distribution which is used when data can be placed into specific categories, as you can see here, the classes in this distribution is comprised of months.
In the next video we will cover the class limits, how to calculate how many classes to use, and how to calculate the actual limits or widths of each class.
Timestamps
0:00 What Is A Frequency Distribution?
0:12 Class Limits Column For Frequency Distribution
0:18 Hand Tally Column For Frequency Distribution
0:27 Frequency Column For Frequency Distribution
0:34 Relative Frequency Column For Frequency Distribution
1:21 Types Of Frequency Distributions
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