def frequency_analysis(text):
    frequencies = dict()
    total_chars = 0

    for char in text:
        if char.isalpha():
            char = char.lower()
            frequencies[char] = frequencies.get(char, 0) + 1
            total_chars += 1

    items = frequencies.items()
    for char, count in sorted(items, key=lambda i: i[0]):
        frequency = count / total_chars * 100
        print(f"{char}: {frequency:.2f}%")