PPGA 503 FINAL EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED
What is a null hypothesis? What is an alternative hypothesis? How do you report
it?
H0- There is no effect
HA- There IS an effect
"The evidence supports the HA, so we reject the null hypothesis"
"We reject H0 up to the 95% interval"
What is p-value (probability values)?***
1. Refers to the probability that a condition or circumstance would happen just by
chance without experimental intervention.
2. Standard of acceptability is 1 out of 20 or a p-value od < or = 0.05****
What is a type I error?
You believe there's a relationship when there is none, or a false positive.
What is a type II error?
When you don't believe there is a relationship, when there is one, or a false negative.
What is the two-sample t-test used for? how do you test this in stata?
To determine whether a sample is different from an expected value, we are assessing
what's different from each other.
, ttesti var1 var2
What is ANOVA?
Analysis of Variance determines whether more than two unrelated groups are different
from one another by testing a difference in means.
What does a chi-squared test do?
Tests whether proportions in a sample are different from an expectation. Called a
goodness of fit test.
What is ordinary least squares regression? How do you code it in Stata?
It's a means of eliminating "noise" in a dataset so we can see the relationship between
the variables. It uses y=B0+B1 +u as the equation.
regress var1 var2
Bivariate OLS Regression
Seeks to describe the relationship between DV (y) and IV (x). Uses a linear model to
line the observations to generalize the relationship between x and y.
How do we measure correlation?
Using "r". We use r^2 to measure a line between 0 and 1. The closer to 1, the more
positive a relationship (45-degree line). The closer to -1, the more negative a
relationship (45-degree line).
Gauss-Markov Assumptions
Conditions must hold!
COMPLETE SOLUTIONS VERIFIED
What is a null hypothesis? What is an alternative hypothesis? How do you report
it?
H0- There is no effect
HA- There IS an effect
"The evidence supports the HA, so we reject the null hypothesis"
"We reject H0 up to the 95% interval"
What is p-value (probability values)?***
1. Refers to the probability that a condition or circumstance would happen just by
chance without experimental intervention.
2. Standard of acceptability is 1 out of 20 or a p-value od < or = 0.05****
What is a type I error?
You believe there's a relationship when there is none, or a false positive.
What is a type II error?
When you don't believe there is a relationship, when there is one, or a false negative.
What is the two-sample t-test used for? how do you test this in stata?
To determine whether a sample is different from an expected value, we are assessing
what's different from each other.
, ttesti var1 var2
What is ANOVA?
Analysis of Variance determines whether more than two unrelated groups are different
from one another by testing a difference in means.
What does a chi-squared test do?
Tests whether proportions in a sample are different from an expectation. Called a
goodness of fit test.
What is ordinary least squares regression? How do you code it in Stata?
It's a means of eliminating "noise" in a dataset so we can see the relationship between
the variables. It uses y=B0+B1 +u as the equation.
regress var1 var2
Bivariate OLS Regression
Seeks to describe the relationship between DV (y) and IV (x). Uses a linear model to
line the observations to generalize the relationship between x and y.
How do we measure correlation?
Using "r". We use r^2 to measure a line between 0 and 1. The closer to 1, the more
positive a relationship (45-degree line). The closer to -1, the more negative a
relationship (45-degree line).
Gauss-Markov Assumptions
Conditions must hold!
