The average greyhound can reach a top speed of 18.5 meters per second. A particular greyhound breeder claims her dogs are faster than the average greyhound. A sample of 40 of her dogs ran, on average, 19.2 meters per second with a population standard deviation of 1.2 meters per second. With α = 0.05, is her claim correct?
A) Yes, because the test value 0.09 falls in the noncritical region.
B) No, because the test value 0.09 falls in the critical region.
C) Yes, because the test value 3.69 falls in the critical region.
D) No, because the test value 0.70 falls in the critical region.

Question

Quizplus · Accepted Answer

The test statistic is calculated using the formula for a z-test: z = (X̄ - μ) / (σ/√n). Here, X̄ = 19.2, μ = 18.5, σ = 1.2, and n = 40. The calculated z-value is 3.69, which falls in the critical region for α = 0.05, indicating the breeder's claim is statistically significant.

The Average Greyhound Can Reach a Top Speed of 18