Let's say a $\pu{300mL}$ solution of $\ce{CuCl\_2}$ was diluted to $\pu{900mL}$. I am then asked to calculate the concentration of the new solution. My solution to the problem is as follows:

$$\begin{align}M\_1 \times V\_1 &= M\_2 \times V\_2\\[0.5em]
\pu{300mL} \times \pu{4M} &= M\_2 \times \pu{900mL}\\[0.5em]
M\_2 &= \pu{1.33M}\end{align}$$

Now I'm wondering how many significant figures my final answer should have. From what I know, I have to refer to the least significant measurement, which happens to have one significant figure. Should my answer be 1 instead?