Practice Questions for Midterm Exam
2012
Multiple Choice-No justication needed, choose one and only one option.
1) A large p-value implies
a. rejection of the null hypothesis
b. a large t-statistic
c. a large Y sample
d. that the observed value Y sample i

Homework 4 Answers
Instructor: Marco Gonzalez-Navarro
ECMC11 Fall 2012
1- (2pt) Let Y be a Bernoulli random variable with success probability p. Let Y1 , ., Yn be iid draws from this
distribution. Let p be the fraction of successes (1s) in the sample.
Sh

Practice Questions 5
Instructor: Marco Gonzalez-Navarro
ECMC11 Fall 2012
1- Suppose that a researcher, using data on class size (CS) and average test scores (TS) from 100 third grade classes
estimates the OLS regression
T S = 520.4 5.82 CS
a) A classroom

Answers to Practice Questions 5
Instructor: Marco Gonzalez-Navarro
ECMC11 Fall 2012
1- Suppose that a researcher, using data on class size (CS) and average test scores (TS) from 100 third grade
classes estimates the OLS regression
T S = 520.4 5.82 CS
a) A

Homework 4
Instructor: Marco Gonzalez-Navarro
ECMC11 Fall 2012
1- (2pt) Let Y be a Bernoulli random variable with success probability p. Let Y1 , ., Yn be iid draws from this
distribution. Let p be the fraction of successes (1s) in the sample.
Show that

Practice Questions 3
Instructor: Marco Gonzalez-Navarro
ECMC11 Fall 2012
1- Let X N (0, 1). Use the Tables to nd the constant c such that:
a) (c) = 0.50
b) (c) = 0.90
c) (c) = 0.25
2- Suppose X has a normal distribution with mean 1 and variance 4. What is

Answers to Practice Questions 3
Instructor: Marco Gonzalez-Navarro
ECMC11 Fall 2012
1- Let X N (0, 1). Use the Tables to nd the constant c such that:
a) (c) = 0.50 c = 0
b) (c) = 0.90 c = 1.29
c) (c) = 0.25 c = 0.68
2- Suppose X has a normal distribution

Practice Questions 2
Instructor: Marco Gonzalez-Navarro
ECMC11 Fall 2012
1- The following table describes how often students of different years have gone to the museum:
Never
Once
More than once
Freshmen
0.08
0.10
0.04
Sophmores
0.04
0.10
0.04
Juniors
0.0

Answers to Practice Questions 2
Instructor: Marco Gonzalez-Navarro
ECMC11 Fall 2012
1- The following table describes how often students of different years have gone to the museum:
Never
Once
More than once
Freshmen
0.08
0.10
0.04
Sophmores
0.04
0.10
0.04

Practice Questions 1
Instructor: Marco Gonzalez-Navarro
ECMC11 Fall 2012
1- Suppose a random variable X has a discrete distribution with the following probability distribution function:
cx
f or x = 1, ., 5
0
f (x) =
otherwise.
Determine the value of the c

Answers to Practice Questions 1
Instructor: Marco Gonzalez-Navarro
ECMC11 Fall 2012
1- Suppose a random variable X has a discrete distribution with the following probability distribution function:
cx
f or x = 1, ., 5
0
f (x) =
otherwise.
Determine the val