Question

In a city with three high schools, all the ninth graders took a Standardized Test. Glenwood had a mean score of 84 with 279 ninth graders, Central City had a mean score of 92 with 341 ninth graders, and Lincoln High had a mean score of 70 with 166 ninth graders. What is the mean score for all ninth graders in the city? Round to one decimal place.

a. 82.4
b. 82.8
c. 83.2
d. 83.6

Answer 1

To find the mean score for all ninth graders in the city, multiply each mean score by the number of ninth graders, then calculate the weighted average. The mean score is approximately 84.6.

Step-by-step explanation:

To find the mean score for all ninth graders in the city, we need to calculate the weighted average of the mean scores from each school. We can do this by multiplying each mean score by the corresponding number of ninth graders, then summing those products and dividing by the total number of ninth graders.

Glenwood: 84 * 279 = 23556

Central City: 92 * 341 = 31372

Lincoln High: 70 * 166 = 11620

Total number of ninth graders: 279 + 341 + 166 = 786

Mean score for all ninth graders: (23556 + 31372 + 11620) / 786 = 66548 / 786 ≈ 84.6

Therefore, the mean score for all ninth graders in the city is approximately 84.6.