A student uses this apparatus to measure the rate of transpiration in still air and the rate of transpiration in windy conditions.
The student calculates the total loss of water after one hour in mg per cm2

of leaf area × 10-4
for

the plant in still air.
He then repeats this calculation for the plant in windy conditions.

(i) The total leaf surface area from which transpiration occurs is 250 cm2
.

Calculate the loss of water from this plant in still air in mg per hour.