In a study of cell phone usage and brain hemispheric dominance, an internet survey was e-mailed to 6969 subjects randomly selected from an online group involved with ears. there were 1302 surveys returned. use a 0.01 significance level to test the claim that the return rate is less than 20%. use the p-value method and use the normal distribution as an approximation to the binomial distribution. so i'm wondering, how do i find the z-score? the test statistic? ?