Quiz #1 Review (September 5)

Question 1

cross-sectional

Answer 1

data from across different entities form a single period of time

Question 2

time series

Answer 2

data on one thing across different time periods

Question 3

panel data

Answer 3

combination of both cross-sectional and time-series

Question 4

discrete random variable

Answer 4

can only take on a limited number of values

Question 5

continuous random variable

Answer 5

can take on a continuim of possible values

-depends on how many decial places you’re willing to work with

Question 6

probability distribution

Answer 6

list of all the possible values (outcomes) a random variable can take on and the probability that it occurs

Question 7

expected value

Answer 7

weighted average of all possible outcomes for this variable where the weights are the probabilities of each outcome

Question 8

joint probability distribution

Answer 8

the probability that the random variables simultaneously take on certain values
ex: rolling a die and flipping a coin

Question 9

conditional probability distribution

Answer 9

given that one is happening, what’s the probabilty distribution of the other?

given x, what is the prob of y?

Question 10

if the conditional distribution is NOT different than the marginal distribution, then what do we know about the 2 variables?

Answer 10

the 2 variables are independent

Question 11

if the conditional distribution IS different than the marginal distribution, then what do we know about the 2 variables?

Answer 11

the 2 variables are NOT independent

Question 12

covariance

Answer 12

do the 2 random variables move together or change together?