A population is normally distributed with mean 18.3 and standard deviation 1.9. (a) Find the intervals representing one, two, and three standard deviations of the mean. one standard deviation 17.2 X (smaller value) 19.4 x (larger value) two standard deviations 16.1 X (smaller value) 20.5 X (larger value) three standard deviations 15 X (smaller value) 21.6 X(larger value) (b) What percent of the data lies in each of the intervals in part (a)? (Round your answers to two decimal places.) one standard deviation % two standard deviations three standard deviations % %