The number of new business registrations in the Gauteng region was recorded by the Department of Trade and Industries for the period 2007 to 2011.
|
Year
|
Quarter
|
|
1
|
2
|
3
|
4
|
|
2007
|
1 005
|
1 222
|
1 298
|
1 199
|
|
2008
|
1 173
|
1 371
|
1 456
|
1 376
|
|
2009
|
1 314
|
1 531
|
1 605
|
1 530
|
|
2010
|
1 459
|
1 671
|
1 762
|
1 677
|
|
2011
|
1 604
|
1 837
|
1 916
|
1 819
|
Use Excel to perform the following calculations:
(a) Plot the number of new business registrations in the Gauteng region for the period 2007 to 2011.
(b) Calculate a four-period centred moving average and plot it on the same axis.
(c) Calculate quarterly seasonal indexes for new business registrations in the Gauteng region using the ratio-to-moving-average method.
(d) Are new business registrations significantly influenced by seasonal forces? Comment.
(e) Calculate the least squares trendline.
(f) Calculate the seasonally adjusted trend estimates of the number of new business registrations in the Gauteng region for the historical data (i.e. from 2007 quarter 1 to 2011 quarter 4).
(g) Plot the actual time series and the seasonally adjusted trend estimates from (f) on the same axis. How close are the two sets of time series data?
(h) Estimate the number of new business registrations in the Gauteng region for each quarter of 2012.