Question

A USA based cable broadband company wants to compare the average customer satisfaction scores between its east coast and west coast customer bases. The customer survey asks for a score between 1 and 5, with 1 being poor and 5 being excellent. 174 east coast customers are surveyed, and the sample mean is 3.51 with a sample standard deviation of 0.51. For the west coast, 355 customers are surveyed, and the sample mean is 3.24 with a sample standard deviation of 0.52.

a)Create a 95% confidence interval for the average score for west coast customers. Interpret this interval in context of the problem.

b)Now say you consider the difference between the average scores between west coast and east coast. Create a 95% confidence interval for the difference in average scores (specify what difference you are considering).

c)The company wants to investigate if the average score of the east coast customers is higher than the average score of the west coast customers. Write the null and alternative to test this hypothesis.

d)Compute the test statistic for this problem and describe how you would obtain the p-value for this test.

e)Say the p-value is very close to 0. In a sentence or two explain what that means in context of this problem.

Answer 1