To calculate the percent error in Elana's count, we first identify two values: the true or actual value and the recorded value. The actual number of students in her class is 24, while she recorded the number of students as 21.
The percent error can be found by following these steps:
1. Find the difference between the actual number and the recorded number.
The error in counting is the actual number minus the recorded number: 24 - 21 = 3.
2. Divide the error by the actual number to calculate the relative error.
The relative error is the absolute value of the error divided by the actual value (we use the absolute value to ensure the error is always positive):
Relative error = |3 / 24|
3. Multiply the relative error by 100 to find the percent error.
Percent error = (Relative error) × 100
Therefore,
Percent error = (|3 / 24|) × 100
After doing the division and multiplication:
Percent error = (0.125) × 100
This calculation yields a percent error of:
Percent error = 12.5%
Elana's percent error in counting the class total is 12.5%.
