Answer
$T = 2.6~K$
Work Step by Step
We can use Wien's law to find the corresponding temperature:
$\lambda_{max} = \frac{2898~\mu m\cdot K}{T}$
$T = \frac{2898~\mu m\cdot K}{\lambda_{max}}$
$T = \frac{2898~\mu m\cdot K}{1.1~mm}$
$T = \frac{2.898~mm\cdot K}{1.1~mm}$
$T = 2.6~K$
