THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION

Essay

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
Independent random samples of seven assistant professors,five associate professors,and six full professors were asked to estimate the amount of time outside the classroom spent on teaching responsibilities in the last week.Results,in hours,are shown in the accompanying table.

-Without assuming normal population distributions,test the null hypothesis that the population mean times spent outside the classroom on teaching responsibilities are the same for assistant,associate,and full professors.