Why are competitive markets considered more efficient than monopolistic markets?

Why are competitive markets considered more efficient than monopolistic markets? Give economic reasons. Give a real-life example of a market that tends to be competitive and one that tends to be monopolistic. Describe characteristics that support your classification. Is there evidence of efficiency or inefficiency in either of the markets you describe?

Rubric is attached below. Also, two powerpoints are attached below for clarification on the topics assigned.

Minimum of 400 words NOT including the references.

Minimum of 3 other academic sources (NOT including the class textbook).