Calculate value X in Table 1 - AQA - GCSE Biology - Question 3 - 2021 - Paper 1

To find the BMI for Person B and calculate the value of X, we start with the formula:

$$BMI = \frac{\text{body mass}}{\text{height}^2}$$

Substituting the values for Person B (body mass = 92 kg, height = 1.71 m), we have:

$$X = \frac{92}{(1.71)^2}$$

Calculating the denominator:

$$(1.71)^2 = 2.9241$$

Now substitute this value back into the BMI formula:

$$X = \frac{92}{2.9241} \approx 31.46$$

Finally, rounding this to 3 significant figures gives:

$$X \approx 31.5 \text{ kg/m}^2$$