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 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?
A popular restaurant advertises that it delivers its orders within 30 minutes. Suppose the average delivery time for one store is 27 minutes with a standard deviation of three minutes. One particular order delivery has a z-score of –2.15. Which of the following statements is not a correct interpretation?
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. What is the test grade, rounded to the nearest whole number, with a z-score of 2.4?
Claire wants to determine how her math score, 690, on a standardized college entrance exam compares to her mother’s score, 680, when she took the exam 20 years earlier. The year Claire took the exam, the mean math score was 510 with a standard deviation of 110 points. When Claire’s mother took the exam, the mean math score was 490 with a standard deviation of 100 points. Who had the better relative performance?
A sample of 10 packs of a brand of chewing gum was taken. Each pack was weighed and their weights, in grams, are shown.43.0, 43.7, 49.6, 46.9, 47.6, 45.4, 51.2, 48.0, 40.5, 49.1
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
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. What is the z-score for a gestation period that lasts 290 days?
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