Finding the final temperature
The energy amount used for heating up a material can be calculated according to the following equation:
$$ E = c_\text{s}\, m\, \Delta T$$
where $E$ is the energy, $c_\text{s}$ the specific heat capacity, $m$ the mass of the object and $\Delta T$ the temperature difference that is to be achieved.

Solving the above equation for $\Delta T$ we get:
$$ \Delta T = \frac{E}{c_\text{s}\, m}$$

Plugging in the values provided by you, I get $\Delta T = 22.6\;\mathrm{K}$ (or °C, since we're talking about the difference and the scale is the same, it doesn't matter).

Adding this increase in temperature to the initial temperature gives the final answer:
$$ \vartheta_\text{f} = \vartheta_\text{i} + \Delta \vartheta = 21.0\; \mathrm{°C} + 22.6\; \mathrm{°C} = 43.6\; \mathrm{°C}$$

Note the following:


Number of significant digits: Since the data given consistently had three significant digits, I've rounded to the third digit.
Symbol for temperature: I used $\vartheta$ for temperatures in °C and $T$ for temperatures in K. I strongly suggest you follow this example as to never confuse the two.