Find the mean of the marks obtained by 20 students in a classroom
MarksFrequency872783531982922971812652983762
83.8
Average or the mean value of a given number of observation is the sum of all observations divided by the number of observations. So, try to obtain the total marks obtained by 20 students in the classroom.
Marks(xi)Frequency(fi)xifi8721747832345315398219692218497197812162652130983294762152TOTAL201676
Mean = ∑xifi∑fi = 167620 = 83.8 i.e. sum total of the marks obtained by 20 students divided by the total number of students.