Answer:
a) 764.45K 
b) 210.48 kJ/kg 
c) 30.14%
Explanation:
pressure ratio = 10
minimum temperature = 295 k
maximum temperature = 1240 k 
isentropic efficiency for compressor = 83%
Isentropic efficiency for turbine = 87%
<u>a) Air temperature at turbine exit </u>
we can achieve this by interpolating for enthalpy 
h4 = 783.05 kJ/kg ( calculated in the background ) at state 4 using Table A-17  for  Ideal gas properties of air 
T4 ( temperature at Turbine exit ) = 760 + ( 780 - 760 )  = 764.45K
 = 764.45K 
<u>b) The net work output </u>
first we determine the actual work input to compressor
Wc = h2 - h1  ( calculated values )
      = 626.57 - 295.17 =  331.4 kJ/kg
next determine the actual work done by Turbine
Wt = h3 - h4  ( calculated values ) 
      = 1324.93 - 783.05 = 541.88 kJ/kg
finally determine the network output of the cycle 
Wnet = Wt - Wc 
          = 541.88 - 331.4  = 210.48 kJ/kg 
<u>c) determine thermal efficiency </u>
лth = Wnet / qin  ------ ( 1 ) 
where ; qin = h3 - h2 
<em>equation 1 becomes </em>
лth = Wnet / ( h3 - h2 )
       = 210.48 / ( 1324.93 - 626.57 ) 
       = 0.3014  =  30.14%