We want to test a large data set for normalcy using the empirical rule. The sample mean is 25, and the sample variance is 25. The data set is large enough that we think these are good estimates of the population parameters. If the data are normally distributed, we'd expect to find 68% of the observations between which two values? A. (25, 50) O B. (25, 35) O c. (0, 50) O D. (15, 35) O E. (20, 30)