Question: Emergency team responds to calls in a mean time of 8.4 minutes with a standard deviation of .7. A new dispatching system is being tested to see if response time can be lowered. If a sample of 18 calls with the new system were answered in mean time of 7.8 minutes, test at the .05 level. State hypotheses and identify claim, find critical value(s), compute test value, make decision, summarize results.