Question

In a psychology class, 53 students have a mean score of 90.9 on a test. Then 21 more students take the test and their mean score is 67.9. What is the mean score of all of these students together? Round to one decimal place. mean of the scores of all the students =

Answer 1

84.4.

Explanation:

To find the mean score of all the students together, you can calculate the weighted mean.

First, calculate the total sum of scores for the initial 53 students and the additional 21 students:

For the initial 53 students:

Mean score = 90.9

Total sum of their scores = 53 * 90.9 = 4812.7

For the additional 21 students:

Mean score = 67.9

Total sum of their scores = 21 * 67.9 = 1425.9. Now, add the total sums of scores for both groups of students:

Total sum of scores for all students = 4812.7 + 1425.9 = 6238.6

Finally, find the mean score of all the students together by dividing the total sum by the total number of students

(53 initial students + 21 additional students):

Total number of students = 53 + 21 = 74. Mean score of all students = Total sum of scores / Total number of students

Mean score of all students = 6238.6 / 74 ≈ 84.4 (rounded to one decimal place)

So, the mean score of all the students together is approximately 84.4.