AQA GCSE · Question 02.4 · Homeostasis and Response
Students investigated their reaction times using a computer program. Table 1 shows the results. Calculate mean value X in Table 1.
How to approach this question
1. Identify the results for Student S from the table: 320, 304, 315, 308, 313.
2. To calculate the mean, first add all these values together (the sum).
3. Count the number of values (there are 5 tests).
4. Divide the sum of the values by the number of values.
Full Answer
The mean is calculated by summing all the data points and dividing by the number of data points.
The reaction times for Student S are: 320, 304, 315, 308, and 313.
Step 1: Sum the values.
320 + 304 + 315 + 308 + 313 = 1560
Step 2: Count the number of values.
There are 5 values.
Step 3: Divide the sum by the count.
Mean (X) = 1560 / 5 = 312 milliseconds.
Common mistakes
✗ Making an error in addition.
✗ Dividing by the wrong number (e.g., 4 instead of 5).
✗ Calculating the mean for the wrong student.
Expert