Answer 7.4

7.4

=> s den/prop (p) 25c/temp (p) 1013hpa/pres and o10/syst
         27221 DEN/PROP
        159833 TEMP/PROP
         51633 25C/UNIT1
         46275 25C/TEMP
                 (TEMP/PROP(S)25C/UNIT1)
         21981 PRES/PROP
           739 1013HPA/UNIT2
           474 1013HPA/PRES
                 (PRES/PROP(S)1013HPA/UNIT2)
            23 DEN/PROP (P) 25C/TEMP (P) 1013HPA/PRES
        117459 O10/SYST
L1          16 DEN/PROP (P) 25C/TEMP (P) 1013HPA/PRES AND O10/SYST

=> d qrd