prelim-1-spring-2019

.pdf

School

Cornell University *

*We aren’t endorsed by this school

Course

3120

Subject

Economics

Date

Apr 3, 2024

Type

pdf

Pages

18

Uploaded by AgentThunderSnake50 on coursehero.com

Department of Economics Econ 3120 Cornell University Applied Econometrics Spring 2019 Prelim 1 — Spring 2019 GENERAL INSTRUCTIONS: Write your name here: You can use any notes you have written (or printed) on a single sheet of paper. You may use a calculator as long as you don’t use it to store additional notes or connect to the Internet. You may not use a cell phone, the internet, make phone calls, or send text messages during the exam. Show your work. Please write as neatly as you can. If you need to make assumptions, please clearly state them in your answer. 1
Question 0. Brief Survey on Studying (2 points) Your answers to these questions have absolutely no impact on your exam score, and I will remove all your names before I analyze this data. (1) How much of the material we’ve covered since the review module (i.e., experiments and bivariate regression) had you seen before? a. none b. some c. almost all or all (2) We’ve had 9 classroom lectures so far this term. How many did you attend in person? (3) Not including attending lectures, how much time have you spent on this class each week doing things like reading or working on problem sets? a. less than one hour b. 1-2 hours c. 3-4 hours d. 5-6 hours e. 7+ hours (4) How much time did you spend studying for this prelim? a. less than one hour b. 1-4 hours c. 4-8 hours d. 9+ hours (5) Did you mostly study for this prelim by yourself or with other students in the class? a. mostly by yourself b. mostly with other students in the class c. about half by yourself and half with other students in the class (6) When did you do most of your studying for this prelim? a. the day before and day of the exam b. spread over multiple sessions over multiple days starting before the night before the exam 2 O at o o o o
(7) What did you do to study for this prelim? (Choose all that apply) a. Review the lecture slides and/or your notes b. Read the book c. Identify areas or topics you are struggling with and get help (e.g., in o ffi ce hours or on the course discussion board) d. Study the problem sets and solutions e. Re-work problems from the problem sets f. Work new sample problems g. Explain or teach the material to someone else 3 8 O o o
Question 1. Probabilities in School and Business (23 points) Suppose a college student is taking three courses: a two-credit course, a three- credit course, and a four-credit course. The expected grade in the two-credit course is 3.5, while the expected grade in the three- and four-credit courses is 3.0. (a) What is the expected overall grade point average for the semester? Re- member that each course grade is weighted by its share of the total number of units. 4 2 3 4 9 E x 305127 3134 413 3.11 EPA random variable weighted avg of grades in the 3 classes
Let X denote the annual salary of workers in Columbus, Ohio, meaured in thousands of dollars. Suppose that the average salary is 52.3, with a standard deviation of 14.6. (b) Find the mean and standard deviation when salary is measured in dollars. (c) If you took a random representative sample of 1000 workers, would you expect the distribution of salary in your sample to be normal? Why or why not? Would you expect the distribution of the sample mean to be normal? Why or why not? 5 let 4 10004 represet salary measured in ELY ELLOOOX 1000 EX 452,300 SDLY Farfooxs 1,000,00 4.62 5141600 n large sample salary distribution similar to distribution in the population Pop dist likely non normal ble bounded at O on bottom has a long tail at the top Sample mean should be approx norm distributed Dlc CLT
Much is made of the fact that certain mutual funds outperform the market year after year (that is, the return from holding shares in the mutual fund is higher than the return from holding a portfolio such as the S&P 500). For concreteness, consider a 10-year period and let the population be the 4,170 mutual funds reported in The Wall Street Journal on January 1, 1995. By saying that performance relative to the market is random, we mean that each fund has a 50-50 chance of outperforming the market in any year and that performance is independent from year to year. (d) If performance relative to the market is truly random, what is the proba- bility that any particular fund outperforms the market in all 10 years? (e) Of the 4,170 mutual funds, what is the expected number of funds that will outperform the market in all 10 years? 6 Pr outperforming any given year Preformance independent year to year Outperforming all 10 years 510 000977 n 4170 p org rta Binomial random variable EE np 4.07
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help