Question 2 • Mathematics for College Liberal Arts Sem 1 (1207350) BCPS 2025-26
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?
Answer
A
The length of this gestation period was longer than the mean length of gestation periods by 1.7 days.
B
The length of this gestation period was shorter than the mean length of gestation periods by 1.7 days.
C
The length of this gestation period was longer than the mean length of gestation periods by 1.7 standard deviations.
D
The length of this gestation period was shorter than the mean length of gestation periods by 1.7 standard deviations.
Explanation
A z-score tells how many standard deviations a value is from the mean. Since the z-score is −1.70, the gestation period was 1.7 standard deviations below (shorter than) the mean. Therefore, choice D is correct; the z-score does not mean it was shorter by 1.7 days.
AI-written and checked against the verified answer.