A population has mean -18 and standard deviation a-5. Round the answers to two decimal places as needed. Part 1 of 3 (a) Find the z-score for a population value of 3. The z-score for a population value of 3 is-3 Part 2 of 3 (b) Find the z-score for a population value of 13. The z-score for a population value of 13 is -1 Part: 2/3 Part 3 of 3 (c) What number has a z-score of 2.2? has a z-score of 2.2. X