10.5 Research and development spending.
The National Science Foundation collects data on the research and development spending by universities and colleges in the United States.3 Here are the data for the years 2008–2011:
Year | 2008 | 2009 | 2010 | 2011 |
---|---|---|---|---|
Spending (billions of dollars) | 51.9 | 54.9 | 58.4 | 62.0 |
(Comment: These are time series data. Simple regression is often a good fit to time series data over a limited span of time. See Chapter 13 for methods designed specifically for use with time series.)
10.5
(a) The spending is increasing linearly over time. (b) ˆy=−6735.3+3.38x.
(c) 0.17, −0.21, −0.09, 0.13. s=0.22136.
(d) SPENDING=β0+β1×YEAR+ε. The estimate for β0 is −6735.5, the estimate for β1 is 3.38, and the estimate for ε is 0. (e) 68.63.