Unformatted text preview: UF-ESI-6321 UF-ESI-6321-12-11-12.xmcd page 1 of 1 12.11.12 Are the following statements true or false? (c) The standard fitted regression line is obtained from a least squares fit. TRUE. As state on page 542, "The fitted line minimizes the sum of squared vertical deviations." (d) In general, extrapolation should be avoided if possible, but it is not as risky as interpolation. FALSE. As stated on page 546, it is best to use the regression model "only for production values x that are close to the values xi in the data set ... extrapolation ... may give inaccurate results." (e) Prediction bands are narrowest at the sample average of the input variable. TRUE. As stated on page 566, "The prediction bands ... are narrowest at x-bar ...." (f) A small value of the coefficient of determination indicates that the regression cannot be statistically significant. FALSE. As stated on page 571, "[A] low value of R2 should not necessarily be interpreted as implying that the fitted regression line is not appropriate or is not useful. A fitted regression line may be accurate and informative even though a small value of R2 is obtained because of a large error variance 2." (i) A simple linear regression model has three unknown parameters. TRUE. As stated on page 536, "The three unknown parameters, the intercept parameter 0, the slope parameter 1, and the error variance 2, are estimated from the data set." Luther Setzer 1 NASA Pkwy E Stop NEM3, Kennedy Space Center, FL 32899 (321) 544-7435 ...
View Full Document
- Spring '07
- Regression Analysis, fitted regression line