Question

The marks in a subject for 12 students are as follows:

31, 37, 35, 38, 42, 23, 17, 18, 35, 25, 35, 29

For the given data, find the 

1. Range 
2. Mean 
3. Median 
4. Mode

Answer 1

Given data is 31, 37, 35, 38, 42, 23, 17, 18, 35, 25, 35, 29.

Rearranging the given data in ascending order,

17, 18, 23, 25, 29, 31, 35, 35, 35, 37, 38, 42

a. Range = Highest observation – Lowest observation

= 42 – 17

= 25

b. Mean = `"Sum of all observations"/"Total number of observations"`

= `(17 + 18 + 23 + 25 + 29 + 31 + 35 + 35 + 35 + 37 + 38 + 42)/12`

= `365/12`

= 30.41

c. Here, n = 12 ...(Even)

Median = `("Value of"  (n/2)"th observation" + "Value of"  (n/2 + 1)"th observation")/2`

= `("Value of"  6"th observation" + "Value of"  7"th observation")/2`

= `(31 + 35)/2`

= `66/2`

= 33

d. Mode = Most frequent observation = 35