Question2 a multiple choice exam consists of 25 questions...

Name: question2 a multiple choice exam consists of 25 questions each with 4 possible answers suppose that a student doesnt know the material and simply guesses on eac1 what is the probability that 38844
Uploaded: 2022-03-25T08:23:33-08:00
Duration: 3 min 27 s
Channel: Audrey Fong
Description: question2 a multiple choice exam consists of 25 questions each with 4 possible answers suppose that a student doesnt know the material and simply guesses on eac1 what is the probability that 38844

Question2: A multiple choice exam consists of 25 questions, each with 4 possible answers. Suppose that a student doesn't know the material and simply guesses on eac1) What is the probability that they get at least 13 questions correct? 0-0.1 0.1-0.2 0.2-0.3 0.3-0.4 0.4-0.5 0.5-0.6 0.6-0.7 0.7-0.8 0.8-0.9 0.9-1.0 Tries 0/2 2) What is the probability that they get more than 3 but less than 10 correct? 0-0.1 0.1-0.2 0.2-0.3 0.3-0.4 0.4-0.5 0.5-0.6 0.6-0.7 0.7-0.8 0.8-0.9 0.9-1.0h question.

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Transcript

00:01 In this question, we are given a four -question multiple choice quiz with five choices for each question.

00:07 And the student guesses at random on each question.

00:10 Let x be the number of correct answers out of these four questions that the student answered.

00:15 Now, x will follow a binomial distribution.

00:18 N is 4.

00:20 And p, the probability of success in a single trial.

00:23 In this case, is the probability of the student guessing a correct answer.

00:27 That will be 1 out of 5.

00:33 And so probability x equals to r, where r is the number of correct answers, will be four choose r, 1 out of 5 to the power of r, and 1 minus 1 out of 5 will be 4 out of 5 to the power of 4 minus r.

00:52 Now in part a, we want to find probability the student gets exactly three questions correct.

00:57 So we're looking at probability of x equals to 3.

01:00 So just sub 3 into the r and you will be able to get the answer.

01:12 And so the answer is 0 .056.

01:21 And rounding, we will get 0 .0263 decimal place.

01:27 Now in b, we want to find the probability the student gets at most three questions correct.

01:35 So at most, that will be x less than equals to three.

01:39 Now, i'm going to take one and minus is complementary case, and that is x is equals to four.

01:48 And so just sub four into the r...