Question

In what ways do advertisers in magazines use sexual imagery to appeal to youth? One study classified each of 1509 full-page or larger ads as "not sexual" or "sexual," according to the amount and style of the dress of the male or female model in the ad. The ads were also classified according to the target readership of the magazine. Here is the two-way table of counts.

	Magazine readership
Model dress	Women	Men	General interest	Total
Not sexual	360	519	241	1120
Sexual	204	89	96	389
Total	564	608	337	1509

(a) Summarize the data numerically and graphically. (Compute the conditional distribution of model dress for each audience. Round your answers to three decimal places.)

	Women	Men	General
Not sexual
Sexual

(b) Perform the significance test that compares the model dress for the three categories of magazine readership. Summarize the results of your test and give your conclusion. (Use α = 0.01.Round your value for χ² to two decimal places, and round your P-value to four decimal places.)

χ2 =
P-value =

Conclusion

Reject the null hypothesis. There is significant evidence of an association between target audience and model dress.Fail to reject the null hypothesis. There is not significant evidence of an association between target audience and model dress.    Reject the null hypothesis. There is not significant evidence of an association between target audience and model dress.Fail to reject the null hypothesis. There is significant evidence of an association between target audience and model dress.

(c) All of the ads were taken from the March, July, and November issues of six magazines in one year. Discuss this fact from the viewpoint of the validity of the significance test and the interpretation of the results.

This is not an SRS. This gives us no reason to believe our conclusions are suspect.This is not an SRS. This gives us reason to believe our conclusions might be suspect.    This is an SRS. This gives us reason to believe our conclusions might be suspect.This is an SRS. This gives us no reason to believe our conclusions are suspect.

Answer 1

a)

	women	men	general interest
not sexual	0.638	0.854	0.715
sexual	0.362	0.146	0.285

b)

applying chi square test:

Expected	Ei=row total*column total/grand total	women	men	general interest	Total
	not sexual	418.61	451.27	250.13	1120
	sexual	145.39	156.73	86.87	389
	Lawyer	564	608	337	1509
chi square    χ2	=(Oi-Ei)2/Ei	women	men	general interest	Total
	not sexual	8.2056	10.1668	0.3330	18.705
	sexual	23.6254	29.2720	0.9587	53.856
	Lawyer	31.831	39.439	1.292	72.561

χ² = 72.561

p value =0.000

Reject the null hypothesis. There is significant evidence of an association between target audience and model dress.

c)

.This is not an SRS. This gives us reason to believe our conclusions might be suspect