Statistics, by its simplest understanding, is the analysis that involves collection, review, and the inference to be drawn from data. While, there is usually a large volume of data involved in this academic discipline, the concept of central tendency deviates from it.
Central tendency focuses on a solitary value for the description of a given set of data. Such function is undertaken with the identification of central position located in the provided data set. There are three ways to measure central tendency – Mean, Median and Mode. It is an arithmetic mean statistics that are being elaborated further.
What is Understood by Arithmetic Mean Statistics?
Definition of arithmetic mean in Statistics simply covers the measurement of average. It involves the addition of a collective of numbers. The resulting sum is further divided with the count of numbers that are present in a given series.
Simple arithmetic mean formula can be understood from the following example –
Say, within a series the numbers are – 36, 46, 58, and 80. The sum is 220. To arrive at arithmetic mean, the sum has to be divided by the count of numbers within the series. Hence, 220 is divided by 4, and the mean comes out to be 55.
Arithmetic mean statistics includes the formula –
[bar{X}] = [frac{(x_{1}+x_{2}+…..+x{n})}{n}] = [frac{sum_{i=1}^{n}xi}{n}]
In the above equation,
X̄ = arithmetic mean symbol ___________________ (a)
X1,…,Xn = mean of ‘n’ number of observations _____ (b)
∑ = summation ______________________________ ©
Concept of Arithmetic Mean Median Mode
Even though arithmetic mean statistics has been elaborated, it can be better understood in the context of median and mode as well.
Within a given data set –
Mean of a data set can comprise of several different series – (1) Individual, (2) Discrete, (3) Continuous, (4) Direct. On the other hand, for calculating the median, the data set has to be arranged in descending or ascending order. Mode covers such data which occurs the most number of times within a given series. The mode formula may be applicable in case of discrete, individual and continuous series.
Finding Arithmetic Mean
Following example illustrates the application of arithmetic mean formula.
|
Scores obtained |
Number of Participants |
|
10 – 20 |
5 |
|
20 – 30 |
5 |
|
30 – 40 |
8 |
|
40 – 50 |
12 |
The Arithmetic Mean Formula in Statistics is –
[bar{X}] = [frac{(x_{1}+x_{2}+…..+x{n})}{n}] = [frac{sum_{i=1}^{n}xi}{n}]
In the first two steps, midpoints of values (f) and aggregate of such values (fi xi) have to be found out.
Midpoint = (upper value) + (lower value) / 2
|
Scores Obtained |
Number of Participants (x) |
Midpoints of Scores (f) |
(fi xi) |
|
10 – 20 |
5 |
(20 + 10)/2 = 15 |
(15 X 5) = 75 |
|
20 – 30 |
5 |
(30 + 20)/2 = 25 |
(25 X 5) = 125 |
|
30 – 40 |
8 |
(40 + 30)/2 = 35 |
(35 X 8) = 280 |
|
40 – 50 |
12 |
(50 + 40)/2 = 45 |
(45 X 12) = 540 |
From the above table, it can be derived –
∑ fi = 30 ………………………………… (i)
∑ fixi = 1020 …………………………… (ii)
Therefore, the arithmetic means of given data amounts to –
X̄ = ∑ fixi / ∑ fi
= 1020/30
= 34
Arithmetic mean statistics can be a complex concept to grasp. You can have all your doubts clarified in ’s online classes. To find out more about this, download the app today!