Students are unprepared for a multiple choice quiz with 25 q

Students are unprepared for a multiple choice quiz with 25 questions. Each question has 5 possible answers. Find mean and standard deviation.

Students are unprepared for a multiple choice quiz with 25 questions. Each question has 5 possible answers.

Let, out of 5 possible answers only one is correct.

Therefore, P(correct)=1/5=0.20

Hence, mean=n*p=25*0.20=5 (n=no. of questions and p=proportion of correct answers)

Standard deviation= [sqrt(n*p*(1-p))] where n=no. of questions and p=proportion of correct answers

Here, n=25,p=0.20. Now putting the values we get:

[sqrt(25*0.20*(1-0.20))]

[=sqrt(25*0.20*080)]

[=sqrt(4)] =2

Therefore, mean=5, standard deviation=2.