Statistics / Mr. Hansen 4/16/2004

Name: __________________________________

Quiz on Chapter 14

Instructions and Scoring. Show all work and answers on separate sheets. Raise your hand if you get stuck. Show as much work as time provides. Justify all steps except for algebraic simplification or area calculations. The calculation of the value of z or t should be shown. Also, for full credit, you should show the details of s.e. and m.o.e. calculations to the extent possible. You will not earn full credit for a correct answer without adequate justification, or a correct answer without correct notation.
	One of the STAtistics students suggested that book thickness (in inches) can be used to predict book length (in pages). We gathered a sample of books, which we will treat here as an SRS even though it really isn't:
	Book Thickness (in.)	Number of Pages
	0.5 1.25 0.925 0.333 0.25 1.1 1.2 0.4	160 790 305 200 77 908 524 152
1.	Construct a scatterplot with LSRL overlaid. Remember that for full credit, you must label the axes and show measurement units.
2.	Compute the slope of the LSRL and interpret its meaning in the context of this problem.
3.	Compute the standard error of the slope, using correct notation.
4.	Compute a 95% confidence interval for the slope, and write your conclusion as a sentence.
5.	Do a full statistical test (all steps) to see if there is evidence that the true r value is positive.