$4.(15$ pt$)$ Humid air at $22,2\backslash$deg C and $40\%$ relative humidity is humidified in an adiabatic spray tower operated at $1$ atm. The air leaving the spray tower has a relative humidity of $60\%.$

Use the psychrometric chart to

a$)$ Determine absolute humidity and the adiabatic saturation temperature of the entering air.

b$)$ Calculate the rate at which water must be added to humidify $750$ kg$/$h of the entering air.

c$)$ The relative humidity and absolute of the exiting air.