Question

In a study of cell phone usage and brain hemisphere dominance an Internet survey was omated to 64 subjects randomly selected from an online group involved with ears. There were 1285 surveys returned Use a 001 significance level of the claim that the return to less than 20%. Use the P value method and use the normal distribution as an approximation to the binomial distribution Identify the hypothesis and alternative typothesis OA Hp02 OBH PO2 Hi #02 Hp02 OCH D02 OD. Hip02 HD 0.2 Hip02 O E Hyp<02 OF H:p>02 Hp02 Hp 0.2 The best statistics (Round to two decimal places as needed.) The values Round to three decimal places as needed) Because the value is the significance level the nul hypothesis. There is evidence to support the claim that the return rate is less than 20%

Answer 1

Solution: Given that, x= 1285, n = 6964 The sample proportion is, 1285 0.1845 = 6964 п Null and alternative hypothesis: Н. : Р20.20 (Left tailed test) H P 0.20 Significance level;a 0.01 Test statistic р-Р Z = Р11-Р) п 0.1845 0.20 0.20(1-0.20) 6964 =-3.23

P-value p P(Z< z - Ф(г) %3D Ф(-3.23) (Standard normal tables = 0.001 Decision rule: Reject Ho. if psa otherwise do not reject Ho Since the p-value is less than the level of significance, so we reject the null hypothesis at the specified significance level. Conclusion: Because the p-value is less than significance level, reject the null hypothesis. There is a sufficient evidence to support the claim that the return rate is less than 20%