The given distribution =
1, 1, 1, 2, 2, 2, 2, 3, 3, 4, 4, 4, 4, 5, 5, 6, 7, 7, 8, 8, 9
To find mean, we have to add the given numbers and divide it by the total number of terms given.
Here 21 total numbers given.
Mean = (1+1+1+2+2+2+2+3+3+4+4+4+4+5+5+6+7+7+8+8+9) /21
= (88)/21 = 4.19 (Approximate upto two decimal place)
Median is the middle value of the distribution.
1, 1, 1, 2, 2, 2, 2, 3, 3, 4, 4, 4, 4, 5, 5, 6, 7, 7, 8, 8, 9
There are 21 numbers given. So middle value is the number in the 11th position.
The number in the 11th position is 4.
So, the median of the distribution = 4
We have to find the difference between mean and median here. To find the difference we have to subtract mean and median.
Therefore, the required difference = 4.19 - 4 = 0.19
0.19 is the required answer here.
So, option b is correct.