MGSC 291 Exam 2 questions with
verified solutions
regression has what type of variable - correct answer ✔✔response variable, that you want to model or
predict as a function of a vector of input features or covariates
marginal distribution - correct answer ✔✔distribution on a variable (unconditional on other variables),
f(y)
conditional distribution - correct answer ✔✔distribution of a variable conditional upon another variable
f(y|x)
conditional mean - correct answer ✔✔the mean of a conditional distribution, example E[y|x]
dates read into R as... - correct answer ✔✔character data, use ".Date" to change to a date
variables such as month are stored as... - correct answer ✔✔numeric and should be changed to a factor
for correct modeling
seasonal variation - correct answer ✔✔patterns that happen regularly within a year
autocorrelation - correct answer ✔✔correlation of a set of numbers with a lagged version of itself
B1 = 1 - correct answer ✔✔random walk, uses return transformation
B1 < 1 - correct answer ✔✔mean-reverting, good for modeling
B1 > 1 - correct answer ✔✔diverting, useless for modeling, likely missing a trend variable
verified solutions
regression has what type of variable - correct answer ✔✔response variable, that you want to model or
predict as a function of a vector of input features or covariates
marginal distribution - correct answer ✔✔distribution on a variable (unconditional on other variables),
f(y)
conditional distribution - correct answer ✔✔distribution of a variable conditional upon another variable
f(y|x)
conditional mean - correct answer ✔✔the mean of a conditional distribution, example E[y|x]
dates read into R as... - correct answer ✔✔character data, use ".Date" to change to a date
variables such as month are stored as... - correct answer ✔✔numeric and should be changed to a factor
for correct modeling
seasonal variation - correct answer ✔✔patterns that happen regularly within a year
autocorrelation - correct answer ✔✔correlation of a set of numbers with a lagged version of itself
B1 = 1 - correct answer ✔✔random walk, uses return transformation
B1 < 1 - correct answer ✔✔mean-reverting, good for modeling
B1 > 1 - correct answer ✔✔diverting, useless for modeling, likely missing a trend variable
