For Steady Flow Through A Heat Exchanger At Approximately Atmospheric Pressure, What Tis The Final Temperature For The Flowing

The attached spreadsheet was distributed. In that spreadsheet you assumed a value of T_out  and then used solver or goal seek to converge on the function corresponding to

f(T_out) = Q – n*R*integral of Cp/R.

Note that your preparation problem should CLEARLY show in BOLD the six step of our methodology. 

also, I upload the answers for each parts 

all you need to do that on excel and in the same format