{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

practice_problems_for_MT2_sol (2)

# practice_problems_for_MT2_sol (2) - Kata Bognar...

This preview shows pages 1–3. Sign up to view the full content.

Kata Bognar [email protected] Economics 41 Statistics for Economists UCLA Fall 2010 Practice Problems for Midterm 2 - suggested solutions - Multiple Choice Questions 1. Which of the following is an example of a discrete random variable? C (a) The weight of a randomly selected box of cookies (b) The length of a randomly selected window frame (c) The number of horses owned by a randomly selected farmer (d) The distance from home to work for a randomly selected worker Explanation: The variables in (a), (b) and (d) are continuous. 2. Sixty percent of children in a school do not have cavities. Let X be the number of children in a random sample of 20 children selected from this school who do not have cavities. The mean of the probability distribution of X is: D 3. There are N balls in an urn, they are either white or red. A sample of n balls is selected without replacement. Denote by X the number of red balls in the sample. D 4. For a normal distribution, the z score for the mean is always: A 5. The area under the standard normal curve that lies between z = 0 and z = 1 . 97 is: B (a) 0.4713 (b) 0.4756 (c) 0.4761 1

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

View Full Document
(d) 0.4745 Explanation: P (0 < Z < 1 . 97) = P ( Z < 1 . 97) - P ( Z < 0) = 0 . 9756 - 0 . 5 = 0 . 4756 .
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• 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.

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

• 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.

Dana University of Pennsylvania ‘17, Course Hero Intern

• 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.

Jill Tulane University ‘16, Course Hero Intern