The police chief wants you to compile statistics about how many crimes are committed by students in November of 2010. He ultimately wants to compare the number of crimes committed by ECU students to those committed by students at all NC public universities; thus, ECU students will be a sample representing students from the population of all NC public university students. We do not know the standard deviation of the population. You interview a random sample of 135 students and find that the mean number of crimes they've committed is 2.5, with a standard deviation of 1.25. a. Calculate the standard error. b. Calculate a 95% confidence interval for this sample mean