Correct spelling, explanation: the word competitive is an adjective from the verb compete and the noun competition. To form an adjective from a verb, we use the end -ive, which means pertaining to, tending to; doing, serving to do. The noun is spelled competition, not competation, therefore the right form is competitive, not competative.

Definition of competitive:
adjective, being focused on competition, wanting to be better at something than other people
I’m scared to be on the opposite team than Sarah, she’s very competitive.
I don’t enjoy the rivalry, I’m not a competitive person.

Incorrect spelling, explanation: the spelling is a mistake because it doesn’t match the spelling of the noun, which is competition. An adjective is always derived from a noun or a verb, so it must accord with the spelling of these parts of speech. Moreover, the word competitive is connected to Latin competit-, past participle stem of competere.

Incorrect spelling

Incorrect spelling