In a study of 420131 cell phone users 121 subjects developed
Solution
POPULATION PROPORTION Z TEST          
           
 Formulating the null and alternatuve hypotheses,          
           
 Ho:   p   =   0.00034
 Ha:   p   =/=   0.00034 [OPTION E]
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 As we see, the hypothesized po =   0.00034      
 Getting the point estimate of p, p^,          
           
 p^ = x / n =    0.000288005      
           
 Getting the standard error of p^, sp,          
           
 sp = sqrt[po (1 - po)/n] =    2.84429E-05      
           
 Getting the z statistic,          
           
 z = (p^ - po)/sp =    -1.83 [ANSWER, ITEM 2]
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 As this is a    2   tailed test, then, getting the p value,  
           
 p =    0.033772018 [ANSWER, ITEM 3]
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 significance level =    0.005      
 Comparing p and the significance value, we   FAIL TO REJECT THE NULL HYPOTHESIS. [OPTION C]
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It is option A. [THERE IS NO SUFFICIENT EVIDENCE THAT THE CLAIM IS TRUE.]

