Writing a letter: two main questions

[piwid]

Dear all,
if I am writing a letter to a woman, and i don't really know her by person, should I write "dear Miss ____" or better "dear Mrs_____"?
Second: if I would like to say, in a really polite way, that I am really sorry for my mistake, should I say "I am really sorry for the inconvenient", or "I am really sorry for the incident" or, again, there are some compound forms that I don't know?
thanks so much for your help
piwid

 

[David]

It is customary these days to ignore the distinction between Miss and Mrs by writing the vague Ms., pronounced Mizz, the old Southern pronunciation used for both Miss and Mrs.

inconvenient is an adjective. I don't know what you are apologizing for, but "I am really sorry for the incident" is clear.

 

[piwid]

thanx really much,
superclear
^__^

 

[Merlino]

Or "I'm really sorry for any incovenience I may have caused you..."

 

[trade14u]

I would definately say "I'm sorry for the inconvenience" as suggested.