The heat gained or lost by a substance undergoing a change in temperature is:
Q = mCpΔT
The heat lost by the iron is equal to that gained by water. The Cp for water is 4.186 Joules/gram
75 x 4.186 x (22.24 - 16.95) = -93.3 x Cp x (22.24 - 65.58)
Cp = 0.411 J/g
The heat capacity of iron is 0.45 J/g
%Error = [(0.45 - 0.41) / 0.41] x 100
%Error = 9.76%