Question: Refer to Exercise, which reported results for the numbers of men and women who had a tattoo.
a. Find a 90% confidence interval for the difference in population proportions of men and women with a tattoo.
b. On the basis of the interval that you computed in part (a), formulate a conclusion about whether the population proportions of men and women with tattoos differ for the populations represented in this study. Explain.
Exercise: In 1998, two statistics classes for students in the liberal arts at a large northeastern university were asked, "Do you have a tattoo?" The responses were as follows:
Yes No
Women 46 227
Men 32 175
a. What proportion of the women in this sample has a tattoo?
b. What proportion of the men in this sample has a tattoo?
c. Compare the men and women, using a bar graph.
d. What population do you think is represented by this sample? In other words, to whom do you think the results can be generalized?
e. For the college women, calculate a 95% confidence interval for the proportion of the population who have a tattoo. Write a sentence that interprets this interval.
f. For the college men, calculate a 95% confidence interval for the proportion of the population who have a tattoo. Write a sentence that interprets this interval.
g. Use the results of parts (e) and (f) to compare college men and women with regard to the proportion who have a tattoo.