midterm2 - Stat 2103 Midterm Exam 2 April 5th NAME 25...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Stat 2103, Midterm Exam 2 April 5th. NAME: 25 points total. You can use the distribution tables, a calculator, and a one-page formula sheet. Problem 1-2. A discrete random variable x can assume possible values 2, 3, 4, and 5. Its probability distribution is shown below. x 2 3 4 5 p ( x ) 0.125 0.375 ? 0.125 1. What is p ( x 4)? a. 0.125; b. 0.25; c. 0.5; d. 0.875. Answer: D 2. Calculate the expected value. a. 3.5; b. 2.5; c. 3; d. 2. Answer: A 3. The ages of a group of 50 men are approximately normal with mean 28 years and a variance of 4 years. For a randomly selected man from this group, the probability of his age falls between 24 and 26 is a. -0.1359; b. 0.1359; c. 0.1499; d. -0.1499. Answer: B 4. The chances of a tax return being audited are 10 in 1000 if an income is less than $100 , 000 and 30 in 1000 if an income is $100 , 000 or more. If four taxpayers with incomes under $100 , 000 are randomly selected, what is the probability that at most one will be audited? a. 0.999; b. 0.001; c. 0.961; d. 0.039. Answer: A Problem 5-6. The number of semester hours of college credit taken by first- time candidates for a certain professional exam has a distribution with a mean of 134 hours and a standard deviation of 14 hours. Consider a random sample of 100 first-time candidates for the exam and let ¯ x represent the mean number of hours of college credit taken for the sample.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern