Question

IT sum 01
.
frequ
class
Marks of 12 students in a unit test are given as 4, 21, 13, 17,5,9,10,20, 19, 12, 20, 14.
Assume a mean and calculate the arithmetic mean of the data. Assume another number as
mean and calculate the arithmetic mean again. Do you get the same result? Comment.
out of 25) scored hy 10 students was 15. One of the student,
8000
Thes​

Answer 1

Answer:

Definition : The arithmetic mean is nearest to assumed mean but not equal.

Marks of 12 students in a unit test are given as 4,21,13,17,5,9,10,20,19,12,20,14.

Arrange the data is ascending order

4,5,9,10,12,13,14,17,19,20,20,21

Assumed mean is almost the median of the data.

Median of 12 terms is M=\frac{6th+7th}{2}M=

2

6th+7th

Median=\frac{13+14}{2}Median=

2

13+14

Median=\frac{27}{2}Median=

2

27

Median=13.5Median=13.5

So, assumed mean = 13.5

Now arithmetic mean = Sum of all observations divided by number of observation:

So,AM =\frac{4+5+9+10+12+13+14+17+19+20+20+21}{12}AM=

12

4+5+9+10+12+13+14+17+19+20+20+21

So,AM =13.66AM=13.66

Thus the arithmetic mean is nearest to assumed mean