Problem 2: A supermarket chain store is currently investigating the customer satisfaction of its northern and southern zone. Survey on a random sample of 90 customers from the northern zone yielded a mean rating of 8.8 points (out of ten) with a standard deviation of 0.7 points. On the other hand, survey on a random sample of 80 customers from the southern zone yielded a mean rating of 9.0 points (out of ten) with a standard deviation of 0.6 points. Can the store management conclude, at a = 0.05, that the customer satisfaction level in the northern and the southern zone are significantly different? [Hint: Check whether to use Z or t. Follow the step- by-step procedure.] *