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

Question

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 gradersGlenwood 78 269Central City 93 321Lincoln High 66 161The city’s PR manager, who never took statistics, claimed the mean score of all ninth graders in the city was 79 . Of course, that is incorrect.

a. What is the mean score for all ninth graders in the city? Round to two decimal places.

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Eva 2 weeks 2021-11-14T00:52:39+00:00 2 Answers 0 views 0

Answers ( )

    0
    2021-11-14T00:54:05+00:00

    Answer:

    Mean score is 81.83

    Step-by-step explanation:

    Mean high score for the following schools and number of students:

    Glenwood:        Score = 78      ,      Students = 269

    Central City:      Score = 93      ,      Students = 321

    Lincoln High:     Score = 66      ,      Students = 161

    Mean score = total score / total number of students

    Total score = (78 * 269) + (93 * 321) + (66 * 161) = 61,461

    Total students = 269 + 321 + 161 = 751

    Mean score = 61,461 / 751 = 81.83

    0
    2021-11-14T00:54:36+00:00

    Answer:

    The mean score for all ninth graders in the city is 82.73.

    Step-by-step explanation:

    We find the weighed mean to find the mean of all ninth graders in the city, that is, we multiply the mean for each high schools by the number of students in the high school, add them, and then divide by the total number of students. So

    M = \frac{78*269 + 93*321 + 66*121}{269 + 321 + 121} = 82.73

    The mean score for all ninth graders in the city is 82.73.

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