Answer:
The statement that best interprets the z-score is;
D. The length of the gestation period was shorter than the mean length of gestation period by 1.7 standard deviations
Step-by-step explanation:
The given parameters are;
The length of the gestation period of the cattle breed = 284 days
The standard deviation = 5.5 days
The z-score of one length of gestation period was z = -1.70
The formula for finding the z-score, z is presented as follows
Where;
x = The observed value for the gestation period
μ = The sample mean length for the gestation period = 284
σ = The gestation period standard deviation = 5.5
When Z = -1.70, we have;
∴ x - μ = -1.7 × σ
∴ x is shorter than μ by 1.7×σ
Therefore, the length of the gestation period, x, was shorter than the mean length of gestation period, μ, by 1.7 standard deviations, σ.