def convert_floats(data):
    """
    Convert string values to float in a list of tuples.

    Args:
        data (list): List of tuples containing string and numeric values.

    Returns:
        list: List of tuples with string values converted to float.
    """
    return [(t[0], float(t[1]), t[2], t[3]) for t in data if isinstance(t[1], str)]