Are the smoking habits (smoker versus nonsmoker) of individuals
related to their cause of death (cancer versus other)? Use the .05
level of significance. Below are the frequency data from a sample
of 150 individuals.
Smoker
Non-smoker
Cancer
46
25
Other
34
45
Here is a table of observed and expected counts for the above
two-way frequency table (expected counts
are in parentheses below the observed counts). Also included in the
table are column percent values.
Observed (Expected) Column %
Smoker
Non-smoker
TOTAL
Cancer
46
(37.87)
57.5%
25
(35.7%)
71
Other
34 (42.5%)
45 (64.3%)
79
TOTAL
80
70
150
Answer the following questions: (clearly label your
answers)
(A)Verbally state the null and alternative hypotheses.
(B) Compute the chi-square statistic (Note: one expected cell
frequency count has been computed for you).
(C) Report the degrees of freedom and the chi-square critical value
using a .05 level of significance.
(D)State your statistical decision and explain why.
(E) Compute Cramer’s Phi. Given the range of Cramer’s Phi (i.e., 0
– 1), describe the strength of the relationship between smoking
habits and cause of death.
(F) Summarize your conclusion in the context of the problem.
(Assume you are reporting this to
someone who has never had a statistics course). (Note: Use the bar
chart to assist with the verbal
interpretation).
(G)Does this study convince you that smoking
causes death by cancer? Explain your answer.