Econ 140
Department of Economics
Fall 2008
Prof. Armando Levy
FIRST MIDTERM EXAM
You have 90 minutes to complete the exam. There are 100 total points. The problems are not
ranked by difficulty. Some statistical tables are attached to the end of this exam. Consult them as
you see fit. Please write your answers on the exam itself and show all work. Good luck.
1.
(20 points) The following table presents some information about the students of the UC
Berkeley in the Fall of 2007:
American
(Y=1)
NonAmerican
(Y=0)
Total
Undergraduate
(X=1)
68%
2%
70%
Graduate
(X=0)
24%
6%
30%
Total
92%
8%
100%
Based on this information:
a.
(5 points) Compute E(Y) and interpret the resulting number.
b.
(10 points) Calculate and interpret E(YX=1) and E(YX=0).
Page 1 of 6
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentEcon 140
Department of Economics
Fall 2008
Prof. Armando Levy
c.
(5 points) A randomly selected student on campus reports that he is non
American. What is the probability that this is an undergraduate student? What is
the probability that this is a graduate student?
2.
This is the end of the preview.
Sign up
to
access the rest of the document.
 Fall '08
 Staff
 Economics, Normal Distribution, Variance, Probability theory, Prof. Armando Levy, Economics Prof. Armando

Click to edit the document details