Question

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 calculate the arithmetic mean again. Do you get the same result? Comment. This question please give the answer

Answer 1

4+21+13+17+5+9+10+20+19+12+20+14=144÷12=12ans

Answer 2

Answer:

The arithmetic mean of the data is 12.75.

Step-by-step explanation:

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

To find : The arithmetic mean of the data?

Solution :

Arranging the data in ascending order,

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

Arithmetic mean is defined as the sum of observation divided by total number of observation.

Assumed mean is consider as the mid value of the data

Median of the 12 even terms data is

$M=\frac{6^{th}+7^{th}}{2}$

$M=\frac{13+14}{2}$

$M=\frac{27}{2}$

$M=13.5$

Assumed mean is 13.5.

Now, The arithmetic mean of the data

$X=\frac{\sum x_n}{n}$

$X=\frac{4+5+9+10+1+13+14+17+19+20+20+21}{12}$

$X=\frac{153}{12}$

$X=12.75$

The arithmetic mean of the data is 12.75.