Question

Give the marks of 10 students of class find out the mean.
Marks obtained : 20, 30, 40, 50, 45, 65, 70, 18, 22, 10

Answer 1

Answer:

Here we have, cumulative frequency distribution less than type. First we convert it into an ordinary frequency distribution. We observe that the number of students getting marks less than 10 is 5 and 9 students have secured marks less than 20. Therefore,  number of students getting marks between 10 and 20 ( inclusive 0 and exclusive 10) is 9−5=4. Similarly, the number of students getting marks between 20 and 30 is 17−9=8 and so on. Thus, we have the following distribution frequency distribution:

Marks: 0−10 10−20 20−30  30−40 40−50 50−60 60−70 70−80 80−90 90−100Number of students:  5    4     8      12      16     15    10      8      5      2Let us Let us now compute arithmetic mean by taking 55 and the assumed mean.

Computation of MeanMarksMid-valueFrequencyui10xi−55fiui0−10 55−5−2510−20 104−4−1620−30  258−3−2430−40 3512−2−2440−50 

hope this helps you...

Answer 2

Answer:

37

Step-by-step explanation:

(20+30+40+50+45+65+70+18+22+10)/10

370/10

37