26 Job Interviews In a Harris poll of 514 human resource pro

26.

Job Interviews In a Harris poll of 514 human resource professionals, 45.9% said that body piercings and tattoos were big grooming red flags. Use a 0.01 significance level to test the claim that less than half of all human resource professionals say that body piercings are big grooming red flags.

Solution

Formulating the null and alternatuve hypotheses,          
          
Ho:   p   >=   0.5
Ha:   p   <   0.5
As we see, the hypothesized po =   0.5      
As it is given,          
          
po =    0.5      
          
Getting the standard error of po, spo,          
          
spo = sqrt[po (1 - po) / n] =    0.022054055      
          
Getting the z statistic,          
p^ =    0.459      
z = (p^ - po)/spo =    -1.859068584      
          
As this is a    1   tailed test, then, getting the p value,  
          
p =    0.031508709      
significance level =    0.01      

Comparing p > 0.01, we   FAIL TO REJECT THE NULL HYPOTHESIS.  

Thus, there is no significant evidence that less than half of all human resource professionals say that body piercings are big grooming red flags. [CONCLUSION]