Why did they provide the value for the enthalpy change of fusion?
You calculated the energy required to change solid gallium at 20&deg;C to solid gallium at 29.76&deg;C.  Once solid gallium reaches 29.76&deg;C, additional energy is required to melt it.  The energy required is given by the $\Delta H_{\text{fusion}}$.  So to complete the question, transform the $\Delta H$ units to a grams basis instead of a mole basis, multiply it by the weight of gallium in the problem, and then add that result to the one you already calculated.  That will be the energy required to change solid gallium at 20&deg;C to liquid gallium at 29.76&deg;C.