Calculating and Interpreting z-Scores Answers

At age six, Kylie is 50 inches tall. Her height has a z-score of 1.8. At age four, Hannah is 48 inches tall. Her height has a z-score of 2.1. Relative to girls their ages, who is taller?

A teacher gave a unit test to both of her statistics classes. The mean test grade for Class A was 77 points, with a standard deviation of 5 points, whereas the mean test grade for Class B was 80, with a standard deviation of 7 points. Kyle, in Class A, received an 82 on the test, and Caleb, in Class B, received an 87. Whose performance on the unit test was better relative to their class?

In a statistics class, students were asked how many siblings they have. Their responses are shown.2, 3, 1, 3, 5, 3, 3, 3, 6, 3, 5, 0, 3

A basketball player averages 22.5 points scored per game with a standard deviation of 6.2 points. In one game, the number of points the athlete scored was 1.2 standard deviations below the mean. Which of the following is the z-score for the number of points scored?

A runner’s distribution of times for running 1,000 meters has a mean of 4.5 minutes with a standard deviation of 0.75 minutes. One of the runner’s times has a z-score of –1.76. What is the runner’s time?

In a certain breed of cattle, the length of gestation has a mean of 284 days and a standard deviation is 5.5 days. What is the z-score for a gestation period that lasts 290 days?

On a unit test in a statistics class, the teacher determines that the mean test grade was 77.5 with a standard deviation of 5.2. One test grade has a z-score of 2.4. Which of the following statements gives the best interpretation of this z-score?

In a certain breed of cattle, the length of gestation has a mean of 284 days and a standard deviation is 5.5 days. One length of gestation had a z-score of –1.70. Which of the following sentences best interprets this z-score?