The following table represents the quarterly value of healthcare claims (in R millions) against all medical health schemes for the period 2007 to 2010.
|
Year
|
Quarter 1
|
Quarter 2
|
Quarter 3
|
Quarter 4
|
|
2007
|
11.8
|
13.2
|
19.1
|
16.4
|
|
2008
|
10.9
|
12.4
|
22.4
|
17.8
|
|
2009
|
12.2
|
16.2
|
24.1
|
14.6
|
|
2010
|
12.8
|
14.5
|
20.8
|
16.1
|
(a) Calculate quarterly seasonal indexes for healthcare claims using the ratio-to- moving-average method.
(b) Derive a trendline using the method of least squares.
(c) Estimate the seasonally adjusted trend value of healthcare claims for each quarter of 2011.
(d) Use Excel's Line with Marker option from the Insert > Chart tab to plot the actual healthcare claims values and the seasonally adjusted trend estimates of healthcare claims values.