Exam 12: Time Series Analysis and Forecasting

A car dealer in Big Rapids,Michigan is using Holt's method to forecast weekly car sales.Currently the level is estimated to be 45 cars per week,and the trend is estimated to be 5 cars per week.During the current week,25 cars are sold.After observing the current week's sales,forecast the number of cars three weeks from now.Use .

Seasonal variations will not be present in a deseasonalized time series.

If the observations of a time series increase or decrease regularly through time,we say that the time series has a random (or noise)component.

Econometric forecasting models,also called causal models,use regression to forecast a time series variable by using other explanatory time series variables.

The most common form of autocorrelation is positive autocorrelation,where large observations tend to follow large observations and small observations tend to follow small observations.

When using exponential smoothing,a smoothing constant must be used.The value for

The smoothing constant used in simple exponential smoothing is analogous to the span in moving averages.

Winter's method is an exponential smoothing method,which is appropriate for a series with trend but no seasonality.

As is the case with residuals from regression,the forecast errors for nonregression methods will always average to zero.

A small p-value in the rune test provides evidence of

To calculate the five-period moving average for a time series,we average the values in the two preceding periods,and the values in the three following time periods.

The data below represents sales for a particular product.If you were to use the moving average method with a span of 3 periods,what would be your forecast for period 5? Period Sales (in units) 1 90 2 120 3 110 4 100

The time series component that reflects a wavelike pattern describing a long-term trend that is generally apparent over a number of years is called cyclical.

The null hypothesis in a runs test is the data series is random.

You will always get more accurate forecasts by using more complex forecasting methods.

The smoothing constants in exponential smoothing models are effectively a way to assign different weights to past levels,trends and cycles in the data.

The moving average method is perhaps the simplest and one of the most frequently-used extrapolation methods.

There are a variety of deseasonalizing methods,but they are typically variations of

A meandering pattern is an example of a random time series.

In a moving averages method,which of the following represent(s)the number of terms in the moving average?