First, you need to understand what absolute error is. Absolute error is the difference between the true value and the measured value. For example, let’s say the true value of something is 100 and the measured value is 97. The absolute error would be 3.
To calculate relative error, you need to divide the absolute error by the true value. In the example above, the true value is 100, so the relative error would be 3/100, which is 0.03 or 3%.
It is important to note that relative error is expressed as a percentage because it is a ratio of two values. It tells you how large the error is relative to the true value. If the relative error is high, it means that the measurement is not very accurate and there is a lot of error present. On the other hand, if the relative error is low, it means that the measurement is very accurate and the error is small.
Here is another example to help illustrate how to calculate relative error. Let’s say you are measuring the length of a table that is 2 meters long. Your measuring tool tells you the length is 1.9 meters. The absolute error would be 0.1 meters (2-1.9). To calculate the relative error, you would divide the absolute error by the true value, which is 2. The relative error would be 0.1/2, which is 0.05 or 5%.
Now that you know how to calculate relative error, you might be wondering how it is used in the real world. Relative error is used in many areas of science and engineering where accurate measurements are important. For example, in the pharmaceutical industry, there is a strict tolerance for the amount of active ingredients in medications. The relative error must be very low to ensure that the correct dosage is administered to patients.
In the field of construction, relative error is used to ensure that buildings are level and safe. If the relative error in the measurements is too high, it could mean that the building is not level and could have structural issues.
In the field of physics, relative error is used to determine the accuracy of measurements that are used in experiments. If the relative error is too high, it could mean that the data collected is not accurate and could lead to incorrect conclusions.
In conclusion, relative error is a way of quantifying how far off a measurement is from the true value. It is calculated by dividing the absolute error by the true value and expressing it as a percentage. Relative error is used in many areas of science and engineering to ensure accurate measurements and data collection. It is an important tool for ensuring the safety and effectiveness of products and processes in many industries.