The median and mode of the distribution are given.
Using the formula for the mean of a frequency distribution:
\[
\text{Mean} = \frac{\text{Mode} + 3 \times \text{Median}}{4}
\]
Substitute the given values:
\[
\text{Mean} = \frac{52 + 3 \times 64}{4} = \frac{52 + 192}{4} = \frac{244}{4} = 49.70.
\]
Thus, the correct answer is \( 49.70 \).