Time Series Analysis DATA-SCIENCE-FOUNDATIONS Practice Questions (Page 5)

Questions 21–25

1. 21application · medium

   An analyst is examining the autocorrelation function (ACF) and partial autocorrelation function (PACF) of a stationary time series. The ACF shows a gradual decay, while the PACF shows a sharp cutoff after one lag. Based on these patterns, which ARIMA model is most appropriate?

   • AARIMA(0,0,1)
   • BARIMA(0,1,0)
   • CARIMA(1,0,1)
   • DARIMA(1,0,0)
   Reveal Solution Discussion Select an answer first
2. 22foundation · easy

   A retail company observes that sales peak every December and drop in January. This repeating pattern at a fixed annual interval is best described as which time series component?

   • AIrregular
   • BCyclical
   • CSeasonality
   • DTrend
   Reveal Solution Discussion Select an answer first
4. 23foundation · easy

   Which component of an ARIMA model captures the dependency between an observation and a linear combination of past forecast errors?

   • AAutoregressive (AR) component
   • BSeasonal component
   • CMoving average (MA) component
   • DIntegrated (I) component
   Reveal Solution Discussion Select an answer first
5. 24foundation · easy

   What is the primary purpose of using a moving average in time series analysis?

   • ATo smooth out short-term fluctuations and highlight longer-term trends.
   • BTo transform the data into a normal distribution.
   • CTo make the series stationary by removing seasonality.
   • DTo increase the variance of the series.
   Reveal Solution Discussion Select an answer first
6. 25application · medium

   A data analyst is fitting an ARIMA model to monthly sales data that shows strong seasonality with a period of 12. The analyst has already determined that first differencing is needed to achieve stationarity. Which ARIMA model specification should the analyst consider to account for the seasonal pattern?

   • AARIMA(0,1,0) with a seasonal component of (0,1,0)12
   • BARIMA(0,1,1) with a seasonal component of (0,1,1)12
   • CARIMA(2,1,2) with a seasonal component of (2,1,2)12
   • DARIMA(1,1,1) without any seasonal terms
   Reveal Solution Discussion Select an answer first