The following data represent petal lengths (in cm) for independent random samples of two species of iris. Petal length (in cm) of Iris virginica: x,; n, = 36 5.2 5.8 6.3 6.1 5.1 5.5 5.3 5.5 16.9 5.0 4. 9 6.0 4.8 6.1 5.6 5.1 5.6 4.8 5.4 5.1 5.1 5.9 5.2 5. 5.4 4.5 6.4 5.3 5.5 6.7 5.7 4.9 4.8 5.8 5.3 5.3 Petal length (in cm) of Iris setosa: X, ; n, = 38 1.6 1.6 1.4 1.5 1.5 1.6 1. 1 12 1.4 1.7 1.0 1.7 1.9 1.6 1.4 1.5 1.4 1.2 1.3 1.5 1.3 1.6 1.9 1.4 1.6 1.5 1.4 1. 6 1.2 1.9 1.5 1.6 1.4 1.3 1.7 1.5 1.6 In USE SALT (a) Use a calculator with mean and standard deviation keys to calculate X1 , S1, X2, and $2. (Round your answers to four decimal places.) X, = 5.4722 X 5 1 = 0.5465 X = 1.4947 X = 0.2163 X (b) Let u, be the population mean for x, and let u, be the population mean for x2 . Find a 99% confidence interval for M, - M2. (Round your answers to lower limit 3.72 X upper limit 4.23 X