$(10$ points$)$ By steadily circulating a refrigerant at low temperature through passages in the walls of the freezer compartment, a refrigerator maintains the freezer temperature at $-4$C when the air surrounding the refrigerator is at $25$C$.$ The rate of heat transfer from the freezer compartment to the refrigerant is $8750$ kJ$/$h and the power input required to operate the refrigerator is $3500$ kJ$/$h$.$ Determine the coefficient of performance of the refrigerator and compare with the coefficient of performance of a reversible refrigeration cycle operating between reservoirs at the same temperatures. $[$MO $1,$ MO $4,$ MO $5,$ MO $6]$