19) (4pts) On a multiple choice test with 21 questions, each question has four possible answers, one of which is correct. For students who guess at all answers, find the standard deviation for the number of correct answers.
A) 15.5
B) 39.4
C) 3.9
D) 2

To make your papers high quality, you - make sure you establish a clear purpose- use a variety of sentence structures and advanced vocabulary - organize the essay effectively to provide a coherent flow of thought/argument- stay on topic! make sure each sentence supports your thesis/argument/purpose - avoid incorrect grammar and mechanics that could detract from your credibility.- use liking words and sentences so your essay flows. as for the new strategies you have learned from the lesson, i think you can draw from he bullet points listed above. hope this !

The answer is number 4.