1) Find the expected count and the contribution to the chi-square statistic for the (Group 1, Yes) cell in the two-way table below.

	Yes	No	Total
Group 1	55	43	98
Group 2	140	65	205
Group 3	65	23	88
Total	260	131	391

Round your answer for the expected count to one decimal place, and your answer for the contribution to the chi-square statistic to three decimal places. Expected count =

contribution to the chi-square statistic =

2) Give the degrees of freedom for the chi-square test based on the two-way table.

	Yes	No	Total
Group 1	56	44	100
Group 2	132	68	200
Group 3	72	28	100
Total	260	140	400

Degrees of freedom =

3) A study is conducted in which people were asked whether they agreed or disagreed with the statement that there is only one true love for each person. The table below gives a two-way table showing the answers to this question as well as the education level of the respondents. A person's education is categorized as HS (high school degree or less), Some (some college), or College (college graduate or higher). Is the level of a person's education related to how the person feels about one true love? If there is a significant association between these two variables, describe how they are related.

HS	Some	College	Total
Agree	364	166	199	729
Disagree	559	467	790	1816
Don't know	18	26	29	73
Total	941	659	1018	2618

Table 1 Educational level and belief in One True Love Round your answer for the chi-square statistic to one decimal place, and your answer for the p-value to three decimal places. chi-square statistic =

p-value = Conclusion:

4) Cocaine addiction is very hard to break. Even among addicts trying hard to break the addiction, relapse is common. (A relapse is when a person trying to break out of the addiction fails and uses cocaine again.) A study is conducted to investigate the effectiveness of two drugs, desipramine and lithium, in the treatment of cocaine addiction. The subjects in the six-week study were cocaine addicts seeking treatment. The 72 subjects were randomly assigned to one of three groups (desipramine, lithium, or a placebo, with 24 subjects in each group) and the study was double-blind. Now we are able to consider all three groups together and test whether relapse rate differs by drug. Ten of the subjects taking desipramine relapsed, 18 of those taking lithium relapsed, and 20 of those taking the placebo relapsed. (a) Create a two-way table from the information given.

Relapse	No relapse	Total
Desipramine

Lithium

Placebo

Total

(b) Find the expected counts.

Relapse No relapse

Desipramine

Lithium

Placebo

Is it appropriate to analyze the data with a chi-square test?

(c) If it is appropriate to use a chi-square test, complete the test, give the chi-square statistic, the p-value, and an informative conclusion.

Round your answer for the chi-square statistic to one decimal place, and your answer for the p-value to three decimal places. chi-square statistic = p-value = Conclusion:

Does the test indicate an association between the type of drug and relapse rate? If the results are significant, which drug is most effective? Can we conclude that the choice of treatment drug causes a change in the likelihood of a relapse?

5) A poll sampled 81 people, asking them their favorite skittle flavor by color (green, orange, purple, red, or yellow). A separate poll sampled 103 people, again asking them their favorite skittle flavor, but rather than by color they asked by the actual flavor (lime, orange, grape, strawberry, and lemon, respectively). The table below shows the results from both polls. Does the way people choose their favorite Skittles type, by color or flavor, appear to be related to which type is chosen?

Green (Lime)	Orange	Purple (Grape)	Red (Strawberry)	Yellow (Lemon)
Color	22	11	18	16	14
Flavor	16	19	23	34	11

Table 1 Skittles popularity

Green (Lime) Orange Purple(Grape) Red(Strawberry) Yellow(Lemon)

Color --- --- ---- ------- ------

Flavor --- --- ---- ----- --------

How many degrees of freedom do we have for this test? Degrees of freedom =

Calculate the chi-square test statistic. Round your answer to two decimal places. chi-square statistic =

Determine the p-value. Round your answer to three decimal places. p-value =