Answered

Westonci.ca offers quick and accurate answers to your questions. Join our community and get the insights you need today. Get quick and reliable solutions to your questions from a community of seasoned experts on our user-friendly platform. Get detailed and accurate answers to your questions from a dedicated community of experts on our Q&A platform.

Justin now has a final exam today. There are 20 questions with 3 options. Each
question only has one correct answer. He just needs to make a 75 to pass the class
(meaning he needs to get 15 right). What is the probability of him doing so?

Sagot :

Answer: .0142%

Step-by-step explanation:

MrRoyal

The probability that Justin passes his final exam is 0.0147%

How to determine the probability?

The given parameters are:

  • Questions, n = 20
  • Pass mark, x = 25
  • Number of options = 3

Only one of the options can be correct.

So, the probability that he answers a question correctly is:

p = 1/3

To get a pass mark of 75, he must score at least 15.

So, the probability is represented using:

P(x >= 15) = P(15) + P(16) + ..... + P(20)

Each probability is calculated using:

[tex]P(x) = ^nC_r * p^x *(1 -p)^{n - x}[/tex]

Using the above formula, we have:

P(15) = 0.00012546624

P(16) = 0.0000193115

P(17) = 0.00000223803

P(18) < 0.000001

P(19) < 0.000001

P(20) < 0.000001

When the above probabilities are added, we have:

P(x >= 15) = 0.00014720925

Express as percentage

P(x >= 15) = 0.014720925%

Approximate

P(x >= 15) = 0.0147%

Hence, the probability that Justin passes is 0.0147%

Read more about probability at:

https://brainly.com/question/251701

Thanks for using our platform. We're always here to provide accurate and up-to-date answers to all your queries. We hope you found this helpful. Feel free to come back anytime for more accurate answers and updated information. Westonci.ca is here to provide the answers you seek. Return often for more expert solutions.