Chapter 17.4, Problem 22E

The Seneca Children’s Fund (SCF) is a local charity that runs a summer camp for disadvantaged children. The fund’s board of directors has been working very hard in recent years to decrease the amount of overhead expenses, a major factor in how charities are rated by independent agencies. The following data show the percentage of the money SCF has raised that was spent on administrative and fund-raising expenses for a seven-year period.

Year	Period (t)	Expense
1	1	13.9
2	2	12.2
3	3	10.5
4	4	10.4
5	5	11.5
6	6	10.0
7	7	8.5

1. a. Construct a time series plot. What type of pattern exists in the data?
2. b. Develop the linear trend equation for this time series.
3. c. Forecast the percentage of administrative expenses for year 8.
4. d. If SCF can maintain their current trend in reducing administrative expenses, how long will it take them to achieve a level of 5% or less?