Question

11. A quiz has 10 multiple choice questions with 3 choices for each question. Answer the following for someone who randomly chooses answers to the questions.
a. Find the probability for getting exactly 4 correct answers.

Answer: ________________








b. Find the probability for getting at least 2 correct answers.

Answer: ________________









c. Find the probability for getting 2 or 3 incorrect answers.

Answer: ________________

Answer 1

The required probability for
a. 0.2058
b. 0.98  
c.0.016

What is probability?

Probability can be defined as the ration of favorable outcomes to the total number of events.

Let use binomial distribution.
Probability answering a question correctly=1/3 =0.33
Probability of not answering a question correctly
=1–1/3
=2/3
a) Out of 10 probability of answering 4 correctly

=10c4 x (0.33)^4 x (0.66)^6

Upon simplification, 0.2058

b) Find the probability for getting at least 2 correct answers
= 1 - { 10c8 x (0.33)^8 x (0.66)^2+ 10c9 x (0.33)^9 x (0.66)^1 + (0.33)^10}
= 0.98

c).Find the probability for getting 2 or 3 incorrect answers.

10c8 x (0.33)^8 x (0.66)^2 + 10c7 x (0.33)^7 X (0.66)^3
=0.002 + 0.014

= 0.016

Thus the required probabilities are: 0.2058, 0.98 , 0.016

Learn more about probability here:

brainly.com/question/14290572

#SPJ1