A school superintendent wants to know how his district's students did on a nationwide standardized achievement test. The test was administered to all...

A school superintendent wants to know how his district's students did on a nationwide standardized achievement test. The test was administered to all on-site students. Unfortunately, 23 students in an EMR (educationally mentally retarded) program as well as 32 in a gifted program (very high IQ) attend classes off-site and so were not able to be tested. What measure of central tendency best summarizes the performance of all the district's students?