Edexcel IGCSE Biology Arithmetic Mean

Pineapple juice contains a protease called bromelain.
A student uses this method to investigate the digestion of solid gelatine protein by bromelain.
- place solid gelatine protein into a test tube up to a height of 5 cm
- mix $5 \mathrm{~cm}^{3}$ pineapple juice with $1 \mathrm{~cm}^{3}$ of pH 4 buffer
- place $1 \mathrm{~cm}^{3}$ of the pineapple juice and buffer solution on top of the gelatine
- leave for one hour in a water bath set to $37^{\circ} \mathrm{C}$
- measure the height of the solid gelatine and use it to calculate the volume of gelatine that has been digested

Repeat the method three more times.
The diagram shows part of the student's method.

The table shows the student's results for the volumes of gelatine digested at pH 4 .

Calculate the mean volume of gelatine digested in $\mathrm{cm}^{3}$.

Give your answer to two decimal places.

Give your answer to two decimal places.
mean volume = $\mathrm{cm}^{3}$