Final Answer:
The claim that the sample of Los Angeles commute times is from a population with a standard deviation equal to 10 minutes is tested using a parametric test at a significance level of 0.05.
Step-by-step explanation:
To test the claim, we would typically use a t-test since the population standard deviation is unknown. However, the question mentions using a parametric test, and assuming the sample size is sufficiently large, a z-test could be appropriate. The null hypothesis (H0) would be that the population standard deviation is equal to 10 minutes. The alternative hypothesis (H1) would be that the population standard deviation is not equal to 10 minutes. Calculating the z-score involves using the formula Z = (s - σ) / (σ/√n), where s is the sample standard deviation, σ is the hypothesized population standard deviation, and n is the sample size. If the calculated z-score falls outside the critical region at a significance level of 0.05, we would reject the null hypothesis.
It's important to note that this explanation assumes certain conditions are met, such as the sample size being sufficiently large for a z-test, and that the commute times are approximately normally distributed. If these conditions are not met, alternative approaches or tests may be needed.
hypothesis testing and statistical analysis in research studies.