Rex wants to estimate the average finishing time of the approximately 50,000 finishers at the New York City Marathon. He takes a random sample of finishers and records their times.
What type of statical test used in this case?
A. A t-test for a mean
B. A z-test for a proportion
C. A paired t-interval for the mean difference
D. A z-interval for a proportion
E. A t-interval for a mean
