Use the standard normal distribution or the t-distribution to construct a 99% confidence interval for the population mean. Justify your decision. If neither distribution can be used, explain why. Interpret the results. In a recent season, the population standard deviation of the yards per carry for all running backs was 1.23. The yards per carry of 25 randomly selected running backs are shown below. Assume the yards per carry are normally distributed. 2 2.5 7.3 5.5 6.4 4.9 7.1 7.4 3.4 2.7 2.6 3.9 6.1 4.4 5.3 7.5 6.6 2.5 4.9 4.3 4.4 3.7 3.9 6.1 7.5