Question:
Find the average of even numbers from 8 to 1126
Correct Answer
567
Solution And Explanation
Solution
Method (1) to find the average of the even numbers from 8 to 1126
Shortcut Trick to find the average of the given continuous even numbers
The even numbers from 8 to 1126 are
8, 10, 12, . . . . 1126
After observing the above list of the even numbers from 8 to 1126 we find that the difference between two consecutive terms are equal. This means the list of the even numbers from 8 to 1126 form an Arithmetic Series.
In the Arithmetic Series of the even numbers from 8 to 1126
The First Term (a) = 8
The Common Difference (d) = 2
And the last term (ℓ) = 1126
The average of the numbers forming an Arithmetic Series
= The first term (a) + The last term (ℓ)/2
⇒ The average of numbers forming an Arithmetic Series = a + ℓ/2
Thus, the average of the even numbers from 8 to 1126
= 8 + 1126/2
= 1134/2 = 567
Thus, the average of the even numbers from 8 to 1126 = 567 Answer
Method (2) to find the average of the even numbers from 8 to 1126
Finding the average of given continuous even numbers after finding their sum
The even numbers from 8 to 1126 are
8, 10, 12, . . . . 1126
The even numbers from 8 to 1126 form an Arithmetic Series in which
The First Term (a) = 8
The Common Difference (d) = 2
And the last term (ℓ) = 1126
The Average of the given numbers
= Sum of the given numbers/Total number of given numbers
Thus, to find the average of the given numbers, first, we need to find their sum and the total number of given numbers
Finding the number of terms
For an Arithmetic Series, the nth term
an = a + (n – 1) d
Where
a = First term
d = Common difference
n = number of terms
an = nth term
Thus, for the given series of the even numbers from 8 to 1126
1126 = 8 + (n – 1) × 2
⇒ 1126 = 8 + 2 n – 2
⇒ 1126 = 8 – 2 + 2 n
⇒ 1126 = 6 + 2 n
After transposing 6 to LHS
⇒ 1126 – 6 = 2 n
⇒ 1120 = 2 n
After rearranging the above expression
⇒ 2 n = 1120
After transposing 2 to RHS
⇒ n = 1120/2
⇒ n = 560
Thus, the number of terms of even numbers from 8 to 1126 = 560
This means 1126 is the 560th term.
Finding the sum of the given even numbers from 8 to 1126
The sum of all terms (S) in an Arithmetic Series
= n/2 (a + ℓ)
Where, n = number of terms
a = First term
And, ℓ = Last term
Thus, the sum of all terms (S) of the given even numbers from 8 to 1126
= 560/2 (8 + 1126)
= 560/2 × 1134
= 560 × 1134/2
= 635040/2 = 317520
Thus, the sum of all terms of the given even numbers from 8 to 1126 = 317520
And, the total number of terms = 560
Since, the average of the given numbers
= Sum of the given numbers/Total number of given numbers
Thus, the average of the given even numbers from 8 to 1126
= 317520/560 = 567
Thus, the average of the given even numbers from 8 to 1126 = 567 Answer
Similar Questions
(1) What is the average of the first 378 even numbers?
(2) Find the average of odd numbers from 11 to 737
(3) Find the average of the first 2807 even numbers.
(4) Find the average of even numbers from 6 to 590
(5) Find the average of odd numbers from 7 to 275
(6) Find the average of even numbers from 6 to 114
(7) Find the average of even numbers from 12 to 786
(8) Find the average of even numbers from 12 to 768
(9) Find the average of odd numbers from 9 to 1291
(10) Find the average of even numbers from 6 to 192