The first paragraph of a cover letter that accompanies a ...

[Pea0909berry]

The first paragraph of a cover letter that accompanies a questionnaire should explain the purpose of the study.
 
 Indicate whether the statement is true or false

Question 2

Explain the problems of non-normality, heteroscedasticity, and autocorrelation and how researchers can detect each.

[LVPMS]

Answer to Question 1

F
The first paragraph of a cover letter that accompanies a questionnaire should explain why the study is important, not necessarily the purpose of the study.

Answer to Question 2

1 . Non-normality occurs when the errors are not normally distributed. It is detected by inspection of a histogram (frequency distribution) of residuals (errors).
2 . Heteroscedasticity is when the residuals do not have a constant variance, creating a greater spread of data points around some parts of the regression line than others. The best way to see if heteroscedasticity is present is to closely inspect plots of the residuals against each of the independent variables. The White and Breusch-Pagan tests are means of detecting it through a computer program.
3 . Autocorrelation occurs when there are meaningful patterns in the error. To detect this, one checks whether knowing the exact value of the error for one data point predicts anything at all about the error value at another point?

[Pea0909berry]

Excellent

[anyusername12131]

Gracias!