Question

The data contained in <professional> are the number of males employed full time in a professional occupation in Australia from August quarter 1996 to August quarter 2008.

Time period	Male full-time employed professionals ('000)
Aug-96	645.6
Nov-96	675
Feb-97	661.2
May-97	659.9
Aug-97	675.2
Nov-97	700.5
Feb-98	710.7
May-98	697.8
Aug-98	711.1
Nov-98	733.6
Feb-99	751
May-99	730.4
Aug-99	704.2
Nov-99	725.7
Feb-00	735.2
May-00	743.7
Aug-00	742.7
Nov-00	746.4
Feb-01	762.7
May-01	760.5
Aug-01	765.8
Nov-01	752.7
Feb-02	759.6
May-02	768.6
Aug-02	761.1
Nov-02	783.3
Feb-03	793.4
May-03	772.2
Aug-03	768.8
Nov-03	786.9
Feb-04	799.1
May-04	794.7
Aug-04	772.5
Nov-04	782.2
Feb-05	769.7
May-05	798.6
Aug-05	823.3
Nov-05	841.7
Feb-06	848.3
May-06	848.2
Aug-06	838.2
Nov-06	825.1
Feb-07	851
May-07	858.9
Aug-07	856
Nov-07	875.5
Feb-08	889.7
May-08	883.2
Aug-08	887.9

a) Plot the series of data.

b) Calculate linear trend equation and plot the trend line.

c) What are your forecasts of male full-time professional employment in November quarter 2008 and February quarter 2009?

d) Do you think it is reasonable to try to forecast employment in this way? Explain.

Answer 1

a)

Time series plot

The time series plot is obtained in excel by following the step,

Select all the data values > INSERT > Recommended Charts > X Y (Scatter) > Scatter with Smooth Lines and Markers > OK. The screenshot of the chart is shown below,

b) Calculate linear trend equation and plot the trend line.

From the given data points, the independent variable time period is the quarterly time period data and the dependent variable is the number of males employed full time in a professional occupation in Australia.

To add Trend line and linear trend equation value in plot.

Step 1: Write the data values in excel. The screenshot is shown below,

Step 2: Select all the data values > INSERT > Recommended Charts > X Y (Scatter) > OK. The screenshot of the chart is shown below,

Step 3: Click on Add Chart element> Trendline > More options>OK. The screenshot is shown below,

Now tick box for Trendline option: Linear and Display Equation on Chart. The screenshot is shown below,

The chart is obtained. The screenshot is shown below,

c)

The forecast for period 50 (November quarter 2008) and 51 (February quarter 2009) are,

d)

Since the time series plot shows a linear trend between the variables, we can say it is reasonable to try to forecast employment in this way