PPGA 503 Final Exam Question and
answers already passed
What is a null hypothesis? What is an alternative hypothesis? How do you
report it? - correct answer ✔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)?*** - correct answer ✔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? - correct answer ✔You believe there's a relationship
when there is none, or a false positive.
What is a type II error? - correct answer ✔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? - correct
answer ✔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? - correct answer ✔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? - correct answer ✔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? -
correct answer ✔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 - correct answer ✔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? - correct answer ✔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 - correct answer ✔Conditions must hold!
Linear relationship between y and x.
Random sample of data (to make inferences from)
No perfect co-linearity in explanatory variables x
Homoscadasticity: u has the same variance for all values of x.
answers already passed
What is a null hypothesis? What is an alternative hypothesis? How do you
report it? - correct answer ✔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)?*** - correct answer ✔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? - correct answer ✔You believe there's a relationship
when there is none, or a false positive.
What is a type II error? - correct answer ✔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? - correct
answer ✔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? - correct answer ✔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? - correct answer ✔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? -
correct answer ✔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 - correct answer ✔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? - correct answer ✔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 - correct answer ✔Conditions must hold!
Linear relationship between y and x.
Random sample of data (to make inferences from)
No perfect co-linearity in explanatory variables x
Homoscadasticity: u has the same variance for all values of x.
