In a city with three high schools, all the ninth graders took a Standardized Test, with these results: High School Mean score on test Number of ninth graders Glenwood 76 272 Central City 93 325...

In a city with three high schools, all the ninth graders took a Standardized Test, with these results:

The city's PR manager, who never took statistics, claimed the mean score of all ninth graders in the city was 80.7 . Of course, that is incorrect. What is the mean score for all ninth graders in the city? Round to one decimal place.


mean of all ninth grader's scores =