Calculate the 90% confidence interval for the difference (mu1-mu2) of two population means given the following sampling results. Population 1: sample size = 19, sample mean = 20.52, sample standard deviation = 3.10. Population 2: sample size = 9, sample mean = 19.00, sample standard deviation = 2.07. Your answer: O 0.32 < mu1-mu2 < 2.72 -1.66 < mu1-mu2 < 4.70 -1.88 < mu1-mu2 < 4.92 -0.55 < mu1-mu2 < 3.59 O 1.45 < mu1-mu2 < 1.59 -0.82 < mu1-mu2 < 3.87 -0.18 < mu1-mu2 < 3.22 -0.70 < mu1-mu2 < 3.74 O 0.81 < mu1-mu2 < 2.23 -0.47 < mu1-mu2 < 3.51