Final answer:
In the modified block letter style, the sender's address, date, closing, and signature are centered, while the body and inside address are left-justified. No indentation is used, and a readable font size of 12 is recommended.
Step-by-step explanation:
A characteristic feature of the modified block letter style in business correspondence is that, unlike full block format, the sender's address, date, closing, and signature start at the center point of the page, rather than being left-justified. In the modified block style, the body of the letter and the inside address are left-justified and single-spaced, with a double space between paragraphs.
No paragraph of the letter should be indented. The professional appearance of a business letter should be maintained by using a readable font, such as Times New Roman or Arial, and a standard font size such as 12. It is essential to follow these formatting guidelines to present a clear and professional document.