Find the arithmetic mean of

(i) the first eight natural numbers


(ii) the first ten odd numbers


(iii) the first five prime numbers


(iv) the first six even numbers


(v) the first seven multiples of 5


(vi) all the factors of 20

(i) First eight natural no’s are = 1,2,3,4,5,6,7,8


Sum of these numbers = 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 = 36


Arithmetic Mean =


(ii) First ten odd numbers are = 1,3,5,7,9,11,13,15,17,19


Sum of these numbers = 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 = 100


Arithmetic Mean =


(iii) First five prime numbers are = 2,3,5,7,11


Sum of these numbers = 2 + 3 + 5 + 7 + 11 = 28


Arithmetic Mean =


(iv) First six even numbers are = 2,4,6,8,10,12


Sum of these numbers = 2 + 4 + 6 + 8 + 10 + 12 = 42


Arithmetic Mean = 7.


(v) First seven multiples of 5 are = 5,10,15,20,25,30,35


Sum of these numbers = 5 + 10 + 15 + 20 + 25 + 30 + 35 = 140


Arithmetic Mean =


(vi) All factors of 20 are = 1,2,4,5,10,20


Sum of numbers = 1 + 2 + 4 + 5 + 10 + 20 = 42


Arithmetic Mean =


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