The median on a graph is found by first extracting the data points, then ordering them from least to greatest, and lastly identifying the middle number.
Finding the Median from a Graph: A Step-by-Step Guide
Finding the median from a graph involves a few key steps. Let's break it down:
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Extract the Data:
- First, you need to read the data points from the graph. This could be from a bar chart, a line graph, or any other type of visual representation.
- Note down each data point as a numerical value.
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Order the Data:
- Once you have the data, arrange it in ascending order, from the smallest to the largest number. This step is crucial to finding the median. As mentioned in the provided reference ([1:15]), "...These are the numbers from above put in order from least to greatest..."
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Identify the Middle Value:
- Once ordered, find the middle number. If there is an odd number of data points, there will be one single middle number, which is the median. As the reference suggests ([1:15]), "...the next thing you do to find the median is you find the number in the middle and in this case..."
Example:
Let's say you have the following numbers extracted from a graph: 5, 2, 8, 1, 5, 9, 3
- Ordering : After putting them in ascending order, we get: 1, 2, 3, 5, 5, 8, 9.
- Median: The middle number in the sequence is 5.
Even number of data points:
If you have an even set of numbers, you will need to find the mean of the two middle numbers to find the median.
- Order the numbers as in the previous steps.
- Identify the two middle numbers.
- Calculate the average of the two middle numbers and the result is the median.
Example:
Let's say you have the following ordered numbers from a graph: 1, 2, 3, 5, 6, 8
- Middle Values: The middle two numbers are 3 and 5.
- Median: (3 + 5) / 2 = 4. The median of the dataset is 4.
Summary
| Steps | Description | Example |
|---|---|---|
| 1. Extract Data | Read and record all data points from the graph. | (e.g., 2, 5, 1, 8, 5) |
| 2. Order Data | Arrange the data points in ascending order (from smallest to largest). | (e.g., 1, 2, 5, 5, 8) |
| 3. Find the Middle Number (Odd) | Identify the single middle number. This number is the median. | In (1, 2, 5, 5, 8) the median is 5. |
| 3. Calculate the Median (Even) | Find the mean of the two middle numbers by adding them and dividing by 2. The result is the median | In (1, 2, 3, 5, 6, 8), (3+5)/2 = 4, so the median is 4 |
