BIOSTATISTICS

MEAN

MEDIAN

MODE

STANDARD DEVIATION

MEAN DEVIATION

VARIABILITY

AVERAGE

Mean is the most commonly used measure of central tendency. It actually represents the average of the given collection of data. It is applicable for both continuous and discrete data.

It is equal to the sum of all the values in the collection of data divided by the total number of values.

Suppose we have n values in a set of data namely as x1,x2,x3……………….xn then the mean of data is given by:

x¯= x1+x2+x3+……..+xnn

It can also be denoted as:

<m> {Sigma^n{_i=1}x_i}/n </m>

S.No	Name	Runs Scored
1	Alexander	80
2	Aladdin	52
3	Anastasia	40
4	Anushka	52
5	Katrina	70
6	Nikita	1
7	Aryan	6

i) The mean is given by x¯ = ∑ni=1xin
⇒x¯ = 80+52+40+52+70+1+67 / 7
⇒x¯ = 43

The mean of the given data is 43.

ii) To find out the median let us first arrange the given data in ascending order

Name	Nikita	Aryan	Anastasia	Aladdin	Anushka	Katrina	Alexander
Runs	1	6	40	52	52	70	80

As the number of items in the data is odd. Hence, the median is (n+1/2)th observation.

⇒ Median = (7+1/2)th observation = 52

iii) Mode is the most frequent data which is 52.
iv) Range
In statistics, the range is the difference between the highest and lowest data value in the set. The formula is:

Range – Highest value – Lowest value