Question

find the average of 1.2,2.3 3.4,4.5​

Answer 1

Step-by-step explanation:

n(n+1) (n+2)/3

Proof:

To find the sum of the finite series

1.2 + 2.3 + 3.4 +………….. to n terms

The nth term = n(n+1) = n² + n;

Now write down each term separately in a similar manner. We will have two columns , one consisting of the first n natural numbers and the second of their squares n² .

n n²

1 1

2 4

3 9

……..

n n²

Adding,

the sum = ∑ n² + ∑n = n(n+1)(2n+1)/6 + n(n+1)/2 = n(n+1)/2 . [(2n+1)/3 + 1]

= n(n+1)/2 . (2n+4)/3 = n(n+1)/2 . 2(n+2)/3

= n(n+1) (n+2)/3 (Proved)

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Answer 2

Given numbers :-

1.2, 2.3, 3.4, 4.5

Formula for average :-

Sum of numbers/Total number of numbers

Average of the numbers :-

= (1.2+2.3+3.4+4.5)/4

= 11.4/4

Average of your numbers = 2.85