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 =
| High School | Mean score on test | Number of ninth graders |
|---|---|---|
| Glenwood | 79 | 266 |
| Central City | 91 | 330 |
| Lincoln High | 72 | 187 |
mean of all ninth grader's scores =