The mean score of all the students is 79.5 and it is round off into one decimal place.
Mean
Mean refers the average of the given numbers and is calculated by dividing the sum of given numbers by the total number of numbers.
Given,
In a psychology class, 30 students have a mean score of 87.7 on a test. Then 21 more students take the test and their mean score is 67.7.
Here we need to find the mean score of all students.
In order order to find the mean score, we have to calculate the total score of the students by multiplying the mean score by the number of students then we get,
=> 30 x 87.7 = 2631
Similarly, the total score for 21 students is,
=> 21 x 67.7 = 1421.7
So, the 51 students, cumulative score is
=> 2631 + 1421. 7 = 4052.7
Therefore, the mean score is calculated as,
=> 4052.7/51
=> 79.464
When we round off the value into one decimal place then we get
=> 79.5
Therefore, the mean value of all the students is 79.5.
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