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
312 milliseconds.
Working:
Sum of results = 320 + 304 + 315 + 308 + 313 = 1560
Mean = Sum / Number of results = 1560 / 5 = 312
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.
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