Develop a Python function to calculate the sum of a certain number of terms in a fractional series, returning the sum as a formatted string.
Create a function that calculates the sum of a fractional series, starting with `1` and incrementing the denominator of each fractional term by `1/3` relative to the previous term. The function should return the sum of up to the `n`th term in string format, rounded to two decimal places. For example, the sum of the first four terms `(1, 1/4, 1/7, 1/10)` equals `1.49`. ### Parameters - `n` (integer): The number of terms to sum in the series. ### Return Value - Returns a string representing the sum of the first `n` terms in the series. The sum is rounded and formatted to two decimal places. ### Examples ```python # Sum of the first term is 1.00 solution(1) # Returns: '1.00' # The sum of the first three terms is 1.39 solution(3) # Returns: '1.39' # Sum of the first four terms is 1.49 solution(4) # Returns: '1.49' ```