Question

Part II. Applying the Binomial distribution. 1. If x is binomial with n-50, pro.9, use Excel to compute P(x s 40)- 2. A student takes a multiple choice test with 100 questions. Each question has 4 choices and only one choice is correct. The student guesses the correct answer for each question. If xenumber of correct guesses, then x is a binomial random variable. Fill in the following values: a) n b) To pass the test, the student must get 60 or more correct answers. What is the probability the student passes? Note that by the law of complements P(x 60)-1-P(xs 59). To get the answer, click in an empty cell and type "d- BINOMDIST(59,100,0.25,1)". P(student passes)

Answer 1

1) from excel P(X<=40 )=binomdist(40,50,0.9,1) =0.0245

2) a) n=100 ; p=0.25 ; $\mu$ =np =25 ; $\sigma$ =(np(1-p))^1/2 =4.33

b)

P(student passes) =1-binomdist(59,100,0.25,1) =1-~1 =0.0000