The Professor's Response

Hello Professor,
I need help solving 49 in homework 5.4. I have: n=50. p=.25 q=.75
and I am solving P(x>35)

is this correct?
Please help. Thank you.

  See the professor's answer below.

Professor McGukian

Hi Christina,

I believe you are a student in my course, so I do want to mention that you are not required to learn 5.4 in your course. However, you have started the problem incorrectly. The problem reads, "What is the probability that when making random guesses on a fifty question multiple choice exam, with four answer choices for each question, that you miss at least thirty-five of the questions?"

In this case, we are looking for at least which implies X is greater than or equal to 35 not just greater than 35. Also, your x here represents the number of missed questions, so p should equal the probability of an incorrect guess. That means p = 0.75 and q = 0.25. That is opposite of what you have typed above.

Sincerely,

Professor McGuckian

  Back to Ask the Professor