Arithmetic Means(A.M.’s)
Arithmetic Means is a value that comes between two number and series become an Arithmetic series (make a series an Arithmetic Series).
There are mainly two type of Arithmetic Means
1. Single Arithmetic Means
2. n Arithmetic Means
Single Arithmetic means-: Any number is known as single arithmetic means between two numbers if all three term together become arithmetic series.
For example if a and b are two given number and M is Arithmetic Means then series a,M,b must be a arithmetic series
Ex 1,3,5 in this series 3 is Arithmetic Means between 1 and 5
2. n Arithmetic Means between two numbers-: series of n numbers is known as n arithmetic means between two numbers if and only if given number and n number between given number are in arithmetic progression.
example if a,M1,M2,M3.........Mn,b are in arithmetic progression then M1,M2,M3.........Mn are n Arithmetic Means between a and b.
How to find single Arithmetic Means between two numbers
If a and b two numbers and M is Arithmetic Means between numbers
Then according to rule
M-a=b-M
2M=a+b
M= (a+b)/2
Find single A.M between 1 and 7
M=(1+7)/2=4
4 is single Arithmetic Mean between 1 and 7
How to find n Arithmetic Means between two numbers
If a and b two numbers and M1,M2,M3,M4,....Mn is Arithmetic Means between numbers
Then according to rule
a,M1,M2,M3,M4,....Mn,b will be in arithmetic progression
and b = (n+2)th term of arithmetic progression.
tn+2=a+(n+2-1)d
tn+2=a+(n+1)d
tn+2 is b so
b=a+(n+1)d
d=(b-a)/(n+1)
Now we have common difference d so
second term (or M1 first mean)=a+d=a+(b-a)/(n+1)
third term (or M2 second mean)=a+2d=a+2(b-a)/(n+1)
like above we can find all arithmetic mean
Example:
Find 5 Arithmetic Means between 2 and 10
here series will become a,M1,M2,M3,M4,M4,10
we have to find 5 arithmetic mean between 2 and 10
here
a = 2 and and t7=10
so as per formulas tn=a+(n-1)d
10=2+(7-1)d
10-2=6d
d=8/6
now we know common difference so we can find all five terms or means
first mean between 2 and 10 is M1=second term
second term=first term + common difference=2+8/6=20/6
third term=second term+ common difference=20/6+8/6
according to this we can find all five Arithmetic Means between 2 and 10.