wikiHow Calculating Z Score Practice Problems 1. A student scores 85 on a test. The mean score for the test is 75 and the standard deviation is 10. What is the student's z-score? 2. A factory produces light bulbs with a mean lifespan of 1000 hours and a standard deviation of 50 hours. If a bulb lasts for 950 hours, what is its z-score? 3. The average weight of a newborn baby is 7.5 pounds with a standard deviation of 1.2 pounds. A baby weighs 9.1 pounds at birth. What is its z-score? 4. The average height of a man is 5 feet 9 inches with a standard deviation of 2 inches. A man is 6 feet tall. What is his z-score? 5. The average weight of a female college student is 135 pounds with a standard deviation of 15 pounds. If a student weighs 150 pounds, what is her z-score? 6. The average time it takes to complete a task is 45 minutes with a standard deviation of 5 minutes. If it takes 55 minutes to complete the task, what is the z-score? 7. The average salary for a job is $50,000 with a standard deviation of $10,000. If someone earns $60,000, what is their z-score? 8. The average IQ score is 100 with a standard deviation of 15. If someone has an IQ score of 130, what is their z-score? 9. The average height of a woman is 5 feet 4 inches with a standard deviation of 2 inches. A woman is 5 feet 8 inches tall. What is her z-score? 10. The average age of a college student is 21 years old with a standard deviation of 2 years. If a student is 19 years old, what is their z-score? 11. The average time it takes to run a mile is 8 minutes with a standard deviation of 1 minute. If someone runs a mile in 6 minutes, what is their z-score? 12. The average weight of a male college student is 170 pounds with a standard deviation of 20 pounds. If a student weighs 190 pounds, what is his z-score? 13. The average height of a high school student is 5 feet 7 inches with a standard deviation of 3 inches. If a student is 6 feet tall, what is their z-score? 14. The average score on a test is 75 with a standard deviation of 5. If someone scores an 85 on the test, what is their z-score? 15. The average salary for a teacher is $40,000 with a standard deviation of $5,000. If a teacher earns $50,000, what is their z-score? 16. The average weight of a male baby is 8 pounds with a standard deviation of 1.5 pounds. If a baby weighs 9.5 pounds, what is its z-score? 17. The average height of a basketball player is 6 feet 5 inches with a standard deviation of 3 inches. If a player is 6 feet 10 inches tall, what is their z-score? 18. The average time it takes to commute to work is 30 minutes with a standard deviation of 5 minutes. If it takes someone 40 minutes to commute to work, what is their z-score? 19. The average score on a math test is 70 with a standard deviation of 10. If someone scores a 50 on the test, what is their z-score? 20. The average salary for a nurse is $60,000 with a standard deviation of $8,000. If a nurse earns $72,000, what is their z-score? Page