A story describing a date rape was read by 352 high school s

A story describing a date rape was read by 352 high school students. To investigate the effect of the victim\'s clothing on subject\'s judgment of the situation described, the story was accompanied by either a photograph of the victim dressed provocatively, a photo of the victim dressed conservatively, or no picture. Each student was asked whether the situation described in the story was one of rape. Data from an article are given in the accompanying table. Is there evidence that the proportion who believe that the story described a rape differs for the three different photo groups? Test the relevant hypotheses using = .01. (Use 2 decimal places.)

² =  
P-value interval

p < 0.0010

.001 p < 0.01   

0.01 p < 0.05

0.05 p < 0.10

p 0.10

The data  ---Select--- (support do or not support) the conclusion that the proportion who believe the story describes a rape is not the same for the three photo groups.

You may need to use the appropriate table in Appendix A to answer this question.

Solution

a)

Doing an Expected Value Chart,          
          
100   89.0625   85.9375  
28   24.9375   24.0625  
          
Using chi^2 = Sum[(O - E)^2/E],          
          
chi^2 =    29.53029118 [ANSWER, CHI^2 VALUE]

**********************      
          
With df = (a - 1)(b - 1), where a and b are the number of categories of each variable,          
          
a =    3      
b =    2      
          
df =    2      
          
Thus, the p value is, by table,          
          
P < 0.0010   [ANSWER]

************************  
          
As P < 0.01,

The data SUPPORT the conclusion that the proportion who believe the story describes a rape is not the same for the three photo groups. [answer, SUPPORT]