1. In a recently administered IQ test, the scores were distributed normally, with mean 100 and standard deviation 15. What proportion of the test takers scored between 70 and 130?
About 68%
About 84%
About 95%
About 99.5%
2. What is a residual plot in a regression analysis?
A scatter diagram that plots the values of the residuals against the values of the dependent variable
A scatter diagram that plots the values of the residuals against the values of an independent variable
A histogram that plots the frequency of certain value ranges of the residuals
None of the above