You suspect that your Toronto customer support team differs in the time to serve each customer from your Montreal team. You gathered a sample from each group, included in the Excel file. Assume that you know the standard deviation for each population (2.9 for Toronto, 4.2 for Montreal).

Part a) Calculate a 95% confidence interval for the difference between population means.

Part b) You suspect that the population mean for Toronto is different from that of Montreal. Perform a hypothesis test, using the p-value method, at a 90% confidence level. Show all parts of the hypothesis test, including your hypotheses, identification/calculation of the necessary values, your test-statistic calculation, your p-value calculation, and your conclusion.

Please verify what type of test it is, (one-tail, two-tail)