Question

Phil conducts a small experiment and collects some data to estimate the difference in mean times that WSPS and Ajax take in shipping packages. A random sample of 12 online shipments for WSPS shows that it takes 4.3 days on average to deliver the food product with a standard deviation of 0.6 days. A random sample of 12 online shipments for Ajax takes 4.1 days on average to deliver the food product with a standard deviation of 0.9 days. Estimating the confidence interval between these two independent samples at 95%, Phil wants to decide which company is a better option. Phil completes the calculation of the confidence interval.

However, Phil understands that he may need to go beyond the confidence interval and perform the hypothesis tests for the difference between these two population means. Phil hypothesizes that there is no difference in shipping delivery time between these two companies given the sample data. He runs his statistical test to prove his hypothesis. He comes up with a conclusion based on the t-test. Phil submits another report with the test discussed above.

Answer 1