Exam 20: Time-Series Analytics and Forecasting

Biodiesel Sales Biodiesel (a vegetable oil or animal fat based diesel fuel)sales in Nebraska have been recorded over the past 10 months as shown below. ​ ​ -{Biodiesel Sales Narrative} Compute the exponentially smoothed sales with w = 0.4 and w = 0.8.

The Pyramids of Giza The Pyramids of Giza is one of the most visited monuments in Egypt.The number of visitors per quarter has been recorded (in thousands)as shown in the accompanying table: ​ ​ -{The Pyramids of Giza Narrative} Use regression analysis to develop the trend line.

If summer 2011 sales were $12,600 and the summer seasonal index was 1.20,then the deseasonalized 2011 summer sales value would be:

Mattress Sales Monthly mattress sales (in $1,000s)of a mattress store are shown below. ​ ​ -{Monthly Mattress Sales Narrative} Compute the three-month and five-month moving averages.

The cyclical component of a time series

Daily Sandwich Sales The daily sales figures shown below have been recorded in a sandwich shop. ​ ​ -{Daily Sandwich Sales Narrative} Plot the series and the moving averages on the same graph.

Liquor Sales The number of cases of liquor sold by a liquor wholesaler in an 8-year period follows. ​ ​ -{Liquor Sales Narrative} Exponential smoothing with a weight or smoothing constant of 0.2 will be used to forecast liquor sales.The forecast for 2019 is ____________________.

Smoothing time series data by the moving average method or exponential method is an attempt to dampen the effects of seasonal variation.

The effect that business recessions and prosperity have on time series values is an example of the disaster component of a time series.

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:

The method of moving averages is used to:

Given a data set with 15 yearly observations,a 3-year moving average will have fewer observations than a 5-year moving average.

MAD stands for ____________________ absolute deviation.

The method of least squares is used on time-series data for

Regression analysis was used to develop the following equation from 60 observations of quarterly data: = 2500 − 3t− 3Q₁ + 2Q₂ + 5Q₃,where Forecast the next four quarters.

In general,it is easy to identify the trend component of a time series by using:

The manager of a lingerie store believed that her store profits were following an exponential trend.She used statistical software to obtain the following prediction equation of profits: log₁₀(Profits)= 2 + 0.4X.The data she used were from 2011 through 2016,coded 0 to 5.Find the forecast of 2017 profits.

One measure of the accuracy of a forecasting model is the:

The Pyramids of Giza The Pyramids of Giza is one of the most visited monuments in Egypt.The number of visitors per quarter has been recorded (in thousands)as shown in the accompanying table: ​ ​ -{The Pyramids of Giza Narrative} Plot the time series.

Use exponential smoothing,with w = 0.4,to forecast the next value of the time series that follows.