Question

16. 1/3 points Previous Answers My Notes Here is a simple probability model for multiple-choice tests. Suppose that each student has probability of correctly answering question chosen at random from a verse of questions. (A strong student has a higher p than a weak student. The correctness of answers to different questions are independent, Jodi is a good student for whom (a) Use the normal approximation to find the probability that Jodi scores o or lower on a 100-question test(ound the probability to the 4th decimal place.) 0.0278 (b) If the test contains 250 questions, what is the probability that Jodi will score 80% or lower? (Round the probability to the 4th decimal place) 00217

Answer 1

X= no. of correct aus well P= probability of correct answer X~Bin. In, p) ; p = 0.85 n=100 Р Ь. С 36 алло «у» Фо". Сал (во е] 2 PL x 480 7 & 80 100x0.857 [100x0.85 * 0.15 ] = P[ 2 3 -1.4003] = 0.0807 . 1.4003

n=250 0 0 Pl scare 80% or low as } = P[x€ 80% of 250] 0 = P[ xs 200] 0 0 = 0.0196 0