3. What is Arithmetic Mean?
The Arithmetic Mean is the average of the numbers a
calculated central value of a set of numbers. And add up all
the numbers, then divide by how many numbers there are.
3
6. Real Life Use
In our class test exam result
For result of any average equation
Baseball game it use to find batman’s batting average
Any kind of equation that use average there we use
mean
6
8. WHAT IS GEOMETRIC MEAN ?
Geometric mean is defined as the N th positive root of the product of N
variables symbolically,
G.M. =
𝑁
𝑥1 ∗ 𝑥2 ∗ 𝑥3 … . 𝑥𝑁 = (𝑥1 ∗ 𝑥2 ∗ 𝑥3 ∗ ⋯ . 𝑥𝑁)
1
𝑁
Formula:
For ungrouped data:
G.M. = Antilog (
log 𝑥
𝑁
)
For grouped data:
G.M. = Antilog (
f log 𝑥
𝑁
)
12. Example of Ungrouped data:
Calculate the harmonic mean of the number 3,27,9.
Solution:
Total numbers = 3
Take reciprocal of the given number, = (1/3,1/27,1/9)
Now find total numbers/(sum of reciprocal)
= 3/(1/3+1/27+1/9)
= 3/((9+1+3)/27)
= 3*27/13
= 78/13
= 6
Therefore Result of the given data set is 6
12
13. Application of Harmonic Mean:
Average speed
Density
Electricity
In finance
In geometry
In other sciences
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15. WHAT IS MEDIAN ?
The median is the middle value of a set of data.
Formula:
For ungrouped data:
If number of observation N is odd then
𝑁+1
2
th observation is median.
If number of observation N is even then the average of
𝑁
2
th and (
𝑁
2
+1) th
observation is median.
For grouped data:
Median = 𝐿 +
𝑁
2
− 𝑃.𝐶.𝐹
𝑓
∗ ℎ
Where,
L = Lower limit of median class.
N = Total frequency.
f = Frequency of median class.
P.C.F = Preceding cumulative frequency.
h = The size of interval.