MGSC Exam 2 Questions And Answers 100% Verified 2024/2025

MGSC Exam 2 Questions And Answers 100% Verified 2024/2025 what is the first step in processing your data for a time series analysis in R? a.) make all data factors b.) make date variable a factor with factor() function c.) make date variable be recognized as a date in R with the () function - answerc how does R store data variables? a.) as factors b.) as characters c.) as the number of days relative to jan. 1, 1970 - answerc in a time series, regular variation that is repeated within a year is called? a.) non-stationary b.) seasonal c.) a random walk - answerb which of the following types of series are useless for modeling? a.) random walk b.) diverging series c.) mean reverting, stationary - answerb which of the following is the most useful type of series for modeling? a.)random walk b.) diverging series c.) stationary, mean reverting - answerc |beta| < 1 - answermean reverting |beta| > 1 - answerdiverging |beta| = 1 - answerrandom walk If you have a random walk, what should you do? - answeruse the returns transformation for modeling what is true about adding higher than AR(1) lags to a model? a.) the simple interactions of the AR(1) term no longer applies b.) the model always works better for prediction than the model with only the AR(1) term c.) if you need higher lags, you might have missed an important trend or seasonality - answera and c A sales price elasticity greater than -1 implies? a.) an inelastic good b.) a good model fit c.) a random walk d.) a diverging series - answera when you have multiple stacks of time series, for example a time series of monthly sales for 185 stores, you have a.) a random walk b.) mean reverting time series c.) panel data d.) non need for fixed effects - answerc fixed effects are a.) effects that fix your residuals to be uncorrelated b.) are different from random effects which allow for correlations between the error terms c.) are just simply a way to inlclude factor variables into the regression d.) make it unneccesary to check model fit since they fix errors in the regression - answera and b in a linear regression with one predictor variable, Bo is the a.) where the line crosses the y-axis b.) where the line crosses the x-axis c.) the slope of the line - answera