Incorrectly is the correct spelling.
"Rainning" is incorrectly spelled. The correct spelling is "raining."
The root word is correct. Incorrectly has a prefix in- and a suffix -ly on it.
That is the correct spelling of "misspell" (spell incorrectly).
because they think it,s is correct and that is their choice
Correct in what context? Accompanying and accompanied are both in the dictionary, with similar meanings. "accompanyed" is incorrectly spelled.
The correct spelling is "generality" (an observation that groups or stereotypes, often incorrectly).
1950s is the correct way. Most people incorrectly place an apostrophe (1950's) but that is only correct for the possessive.
The problem is being investigated. You should manually change the spelling rather than click on the selection in the list. The spell checker on the answer box will show misspelled words in RED. If you place the mouse near them, possible correct alternates will be shown.
The two zeros after the decimal point indicate that the answer is correct to two decimal places.