question: Norman High School enrolls an average of 4000 students every year. Butler High School, the neighboring school, enrolls an average of 3/4 as many students as Norman High School. How much greater is the average enrollment at Norman High School than the enrollment at Butler High School?
answer: If Norman High School enrolls an average of 4000 students every year, Butler High School school enrolls an average of 3/4*4000 =<<4000*3/4=3000>>3000 students every year.
  The average enrollment at Norman High School is greater than the enrollment at Butler High School by 4000-3000= <<4000-3000=1000>>1000
  #### 1000