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A random sample of 15 emergency reports was selected from the files of an ambulance service. The mean time required for ambulances to reach their destinations was 13.5 minutes with a standard deviation of 6.5 minutes. Assume that the population is normally distributed. a) What is the point estimate for the population mean response time of the ambulance service? Point estimate = Select an answer v minutes b) Construct a 90% confidence interval for the population mean response time of the ambulance service in the following steps. Step1. Find the critical values: i. If you use z-table, then state the closest left cumulative area in the table to find the negative critical value. If you use t-table, then state the two numerical values to find the positive critical value, separated by a comma. ii. CV = + Step 2. Calculate the margin of error: Show your work using the numerical values in the formula and round the answer to one decimal place. (Use + for multiplication. 18 E = minutes Clan O Chainin mathematical