Investigation 5: College drinking habots (assigned Fri Jan 22, due Tues Jan 26)

You may work with one other person on this assignment, handing in one report with both names. Word-processed reports are much preferred to hand-written ones. Please copy/paste relevant, well-labeled Minitab output into a Word file as appropriate.

A study of drinking habits of college students produced the following table of counts:

	Reside On campus	Reside off campus, not with parents	Reside off campus, with parents	Total
Abstain from drinking	46	17	43	106
Light or moderate drinking	126	72	68	266
Heavy drinking	130	52	32	214
Total	302	141	143	586

a) Identify the explanatory and response variables in this study. Also classify each variable as categorical or quantitative.

b) Is this an observational or an experimental study? Explain briefly.

c) For each residence location, determine the sample proportion of students who say that they abstain from drinking alcohol and also the sample proportion of students who say that they engage in heavy drinking.

d) Produce (and submit) a segmented bar graph to display these data. [Hint: You could do this by hand, or use Excel. If you use Excel, enter the category labels and observed counts and then use the Chart Wizard to select a 100% Stacked Column graph.]

e) State the null and alternative hypotheses for a chi-square test on these data.

f) Show how to calculate (by hand) the expected count for the (abstain from drinking, reside off campus with parents) cell of the table.

g) Conduct a chi-square test. Report the test statistic and p-value. [Hint: You can do this by hand, or else with Minitab by typing the observed counts from the table (not including the row and column totals) into three columns, and then use Stat> Tables> Chi-square test.]

h) Summarize the conclusion that you would draw from this chi-square test.

i) Identify which cell(s) of the table contributes the most to the calculation of the chi-square statistic. What does this reveal about a possible relationship between a college student’s location of residence and drinking habits? Explain.