Answer questions 19-23 please! 19 is defined as a. regular variation above and b
ID: 354831 • Letter: A
Question
Answer questions 19-23 please!
19 is defined as a. regular variation above and below the trend line with a cycle completing itself within a year b. regular variation above and below the trend line with a cycle completing itself within a period longer than one year c. a sudden change in process level due to a known cause d. part of the error term 20. The term "stationary data" means that a, the mean is constant b. ther c. the fitted line goes through the origin d. there is no change in the data e is an increasing linear trend over time Seasonal effects are typically modeled using a. the additive model b. the multiplicative model c. (a) and (b) d. neither (a) nor (b) 21. 22. Seasonality in a time series is indicated by a. jegular, repeating patterns in the data around a trend line b tegular patterns in the data around a trend line c. irregular patterns in the data around a trend line d. random patterns in the data around a trend line. 23. Forecasting into distant future periods a. is unreliable b. is expensive C. is easy duassumes changing data patternsExplanation / Answer
Answer:
19.a.regular variation above and below the trend line with a cycle completing itself within a year
Explanation:
The predictable changes in the time series that occurs over a one year period is said to be seasonal
20.a.the mean is constant
Explanation:
In stationary data,the mean,variance all are constant over time and donot change
21.b.multiplicative models
Explanation:
In multiplicative model,the trend has the same dimensions and the seasonality effects are obtained using multiplicative decomposition
22.a.regular repeating patterns in the data around the trend line
Explanation:
Seasonality in time series provides data that are regularly repeated over a period of one year.The changes can be predictable and regular
23.a.is unreliable
Explanation:
Forecasting the nearer periods is certain but for distant future periods the data may be uncertain so the accurate results cannot be predicted and it is unreliable