# math data management

a multiple choice quiz has 10 questions. each question has five possible answers.carman is certain that she knows the correct answers for questions 1 and 4. if she guesses the other questions, determine the probability that she gets 60 % on the quiz ?

i know this question involves binomial distribution but im not sure with the correct format and order that im supposed to put the question in ?

1. 👍 0
2. 👎 0
3. 👁 490
1. she needs at least 4 out of the remaining 8 questions correct. So, that has probability

This topic is discussed here:

1. 👍 0
2. 👎 0
2. The probability of any one getting correct with five possible answers is .2, and to make a 60 she has to get four more right.

P(4 correct)=8C4*(.2)^4(.8)^4=
= 8*7*6*5/4*3*2*1 (.2)^4 * (.8)^4
= 7*2*5 * (.2)^4 (.8)^4
= 70 * 0.00065536
= 0.0458752

Now if you wanted to calculate the probability of getting at least a 60 , then you have to add the Pr of getting 70, 80, 90, 100
Pr(70:5 more right)=8C5 (.2)^5(.8)^3
Pr(80:6 right)=8C6 (.2)^6 (.8)^2
Pr(90:7 right)=8C7 (.2)^7 (.8)
Pr (100: 8 more right)= .2^8

1. 👍 0
2. 👎 0
👨‍🏫
bobpursley

## Similar Questions

1. ### Stats

Richard has just been given a 4-question multiple-choice quiz in his history class. Each question has five answers, of which only one is correct. Since Richard has not attended class recently, he doesn't know any of the answers.

2. ### Probability/Statistics

A quiz consists of 10 multiple-choice questions, each with 4 possible answers. For someone who makes random guesses for all of the answers, find the probability of passing if the minimum passing grade is 70 %. I'm not sure what to

3. ### Math (Algebra)

Gretchen and Ezia received equal scores on a test made up of multiple choice questions and an essay. Gretchen got 18 multiple choice questions correct and received 19 points for her essay. Ezia got 15 multiple choice questions

4. ### Math

Multiple Choice Choose the best answer. For questions 1–3, rewrite the expression using exponents. 4 × 4 × 4 × 4 × 4 A. 54 B. (My choice) 45 C. 44 ====== 3 × 3 × 3 × 3 A. (My choice) 34 B. 43 C. 35 ===== 10 × 10 × 10 A.

1. ### MATH Prob.

Find the probability of correctly answering the first 4 questions on a multiple choice test if random guesses are made and each question has 3 possible answers. A) 4/3 B) 1/81 C)1/64 D)3/4 I automatically think D.

2. ### math

A student takes a multiple choice quiz with 12 questions and 5 alternatives per question. Unfortunately, this student has no idea what any of the answers are, so he randomly selects an alternative for each question on the exam.

3. ### Statistical concept 68-95-99.7

1. A student taking a midterm exam in Ancient History comes to two questions pertaining to a lecture that he missed, and so he decides to take a random guess on both questions. One question is true-false and the other is multiple

4. ### Math

A math quiz is made up of 5 multiple choice questions, each with 4 possible answers. How many possible sets of answers are there?

1. ### statistics

Richard has been given a 5-question multiple-choice quiz in his history class. Each question has three answers, of which only one is correct. Since Richard has not attended the class recently, he doesn't know any of the answers.

2. ### math

Louann and Carla received equal scores on a test made up of multiple choice questions and an essay. Louann got 14 multiple choice questions correct and received 24 points for her essay. Carla got 16 multiple choice questions

3. ### statistics

A multiple choice test has 20 questions with each having 4 possible answers with one correct. Assume a student randomly guesses the answer to every question. 1) What is the probability of getting exactly 9 correct answers? 2)What

4. ### algbrea

Francine and Cheryl received equal scores on a test made up of multiple choice questions and an essay. Francine got 34 multiple choice questions correct and received 14 points for her essay. Cheryl got 30 multiple choice questions