A marine biologist investigated cardiac adaptations in Weddell seals (Leptonychotes weddellii) during different physiological states.
For each state, the biologist determined:
The EF is calculated using the formula:
EF=Stroke VolumeMVV \text{EF} = \frac{\text{Stroke Volume}}{\text{MVV}} EF=MVVStroke Volumewhere Stroke Volume is the volume of blood pumped out of the ventricle during a single contraction.
The table below shows the biologist's results:
| State | Resting on ice | Deep foraging dive |
|---|---|---|
| Mean MVV / cm3\text{cm}^3cm3 | 400 | 320 |
| Mean EF | 0.70 | 0.55 |
Using this table, a student calculated that the percentage change in the stroke volume of the seal during a deep foraging dive compared with its stroke volume when resting on ice is −59.1%-59.1\%−59.1%.
The student's answer is incorrect because they performed the final step of the calculation incorrectly.
Using the formula and the table, calculate the correct percentage change in the stroke volume of the seal during a deep foraging dive compared with its stroke volume when resting on ice. Give your answer to 1 decimal place.
Identify the mathematical error in the final step of the student's calculation.
