In a city with three high schools, all the ninth graders took a Standardized Test, with these results: High School Mean Test Score Number of ninth graders (Frequency) Glenwood 81 284 Central 95 323...

Extracted text: In a city with three high schools, all the ninth graders took a Standardized Test, with these results: High School Mean Test Score Number of ninth graders (Frequency) Glenwood 81 284 Central 95 323 Lincoln 69 154 The city's PR manager, who never took statistics, claimed the mean score of all ninth graders in the city was the average of 81, 95, and 69, which is 81.7. 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 =