Aconsumer advocate agency is concerned about reported failures of two brands of mp3 players, which we will label brand a and brand b. in a random sample of 197 brand a players, 33 units failed within 1 year of purchase. of the 290 brand b players, 25 units were reported to have failed within the first year following purchase. the agency is interested in the difference between the population proportions, pa - pb, for the two brands.(a) from these data, the point estimate of the true difference between the proportions, d pa - pb, and the standard error of the estimate, se, are, respectively d = 0.1191, sed 0.0313 d = 0.0813, sed = 0.0313 d = 0.1191, sed = 0.1049 d = 0.0813, sed = 0.0299 (b) what is the 99% confidence interval estimate of the true difference, pa-pb? (0.0042, 0.1584) (0.0007, 0.1619) (0.0084, 0.1542) (0.1893, 0.3897) (c) if it were believed that the two population proportions were actually equal, i. e., pa ps p , what would be the standard error of the estimated difference, sed? 0.0313 0.0147 0.1049 0.0299