Exam 18: Models for Time Series and Forecasting

Which of the following components of a time series measures the overall general directional movement over a long period of time?

A trend component in a time series model must be expressed as a linear relationship over time using a linear trend equation.

In the MAD criterion,"MAD" stands for ____________________.

Cell Phones The number of peak cell-phones minutes used each month by a particular person is shown in the table below: Manth Minutas 1 74 2 86 3 70 4 96 5 111 6 102 7 115 126 -What is the linear trend estimate for Month 7?

Inventory The following values are the means for each month of the inventory as a percentage of the moving average for the twelve months of the year. 79 86 101 104 112 113 115 110 97 99 93 86 -Compute the de-seasonalized value for February if the inventory in February is $48,000.

The estimated true value of community water consumption is 500,000 gallons for a given month.Assume that the cyclical component is 125% of normal,with seasonal and irregular components 70% and 105% of normal,respectively.Use the multiplicative time series model in determining the quantity of water consumed during the month.

Stock exchange Membership on a stock exchange for five years is given below: Year Members 1996 520 1997 510 1998 505 1999 508 2000 512 -Use the exponential smoothing procedure to obtain estimates of the trend (this is not the logarithm approach here).Set the smoothed value for 1996 equal to the actual and use a smoothing constant, $\alpha$ = 0.4.Compute the forecasted value for 2000.

When values in a time series are highly correlated with each other,____________________ forecasting models can be useful.

The seasonal index is a factor that inflates or deflates a trend value to compensate for the effect of a pattern that repeats over a period of one year or less.

Fill in the blank Interpreting the Durbin-Watson test statistic (d),weak or nonexistent autocorrelation is indicated by a value near ____________________.

In the MSE criterion,"MSE" stands for ____________________.

The analysis of time series data is useful in identifying past patterns and tendencies as well as helping to forecast future values.

The means of the quarterly cost as a percentage of moving average are 151.5,77.5,67.3,and 110.6.Prepare the seasonal index for each quarter.

A common method of testing for autocollinearity (serial correlation)is a Durbin-Watson test.

Susan Young Susan Young is a college student who has just completed her junior year.The table below summarizes her Grade Point Average (GPA)for each of the last nine semesters. Year Semaster CPA Freshman Fall 2.5 Winter 2.8 Spring 2.6 Sophomore Fall 2.4 Winter 3.1 Spring 2.8 Junior Fall 2.6 Winter 3.5 Spring 3.1 -What is the linear trend equation?

What is the Consumer Price Index?

Quarterly sales The quarterly sales (in millions of dollars)of a department store chain were recorded for the years 1997-2000.They are listed below. Year Quarter Sales 1997 1 21 2 36 3 28 4 44 1998 1 25 2 23 3 39 4 36 1999 1 30 2 41 3 47 4 55 2000 1 34 2 29 3 32 4 48 -What can you conclude from your time-series smoothing?

What is the Employment Cost Index?

The time series component that reflects the irregular changes in a time series that are not caused by any other component,and tends to hide the existence of the other more predictable components,is called:

A time series may consist of weekly production output,monthly sales,annual rainfall,or any other variable for which the value is observed or repeated at regular intervals.