Answer: The partial pressure of the water vapor is 1.108 atm
Step-by-step explanation:
According to Dalton's law, the total pressure of a mixture of gases is the sum of individual pressures exerted by the constituent gases.

Thus

Given:
=4.015 atm
= 2.907 atm
= ?
Thus


Thus the partial pressure of the water vapor is 1.108 atm