Question : Find the average of even numbers from 4 to 1786
Correct Answer 895
Solution & Explanation
Solution
Method (1) to find the average of the even numbers from 4 to 1786
Shortcut Trick to find the average of the given continuous even numbers
The even numbers from 4 to 1786 are
4, 6, 8, . . . . 1786
After observing the above list of the even numbers from 4 to 1786 we find that the difference between two consecutive terms are equal. This means the list of the even numbers from 4 to 1786 form an Arithmetic Series.
In the Arithmetic Series of the even numbers from 4 to 1786
The First Term (a) = 4
The Common Difference (d) = 2
And the last term (ℓ) = 1786
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 4 to 1786
= 4 + 1786/2
= 1790/2 = 895
Thus, the average of the even numbers from 4 to 1786 = 895 Answer
Method (2) to find the average of the even numbers from 4 to 1786
Finding the average of given continuous even numbers after finding their sum
The even numbers from 4 to 1786 are
4, 6, 8, . . . . 1786
The even numbers from 4 to 1786 form an Arithmetic Series in which
The First Term (a) = 4
The Common Difference (d) = 2
And the last term (ℓ) = 1786
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 4 to 1786
1786 = 4 + (n – 1) × 2
⇒ 1786 = 4 + 2 n – 2
⇒ 1786 = 4 – 2 + 2 n
⇒ 1786 = 2 + 2 n
After transposing 2 to LHS
⇒ 1786 – 2 = 2 n
⇒ 1784 = 2 n
After rearranging the above expression
⇒ 2 n = 1784
After transposing 2 to RHS
⇒ n = 1784/2
⇒ n = 892
Thus, the number of terms of even numbers from 4 to 1786 = 892
This means 1786 is the 892th term.
Finding the sum of the given even numbers from 4 to 1786
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 4 to 1786
= 892/2 (4 + 1786)
= 892/2 × 1790
= 892 × 1790/2
= 1596680/2 = 798340
Thus, the sum of all terms of the given even numbers from 4 to 1786 = 798340
And, the total number of terms = 892
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 4 to 1786
= 798340/892 = 895
Thus, the average of the given even numbers from 4 to 1786 = 895 Answer
Similar Questions
(1) What will be the average of the first 4735 odd numbers?
(2) Find the average of odd numbers from 9 to 185
(3) Find the average of odd numbers from 5 to 1155
(4) Find the average of the first 2911 even numbers.
(5) Find the average of odd numbers from 5 to 115
(6) Find the average of the first 3114 even numbers.
(7) What is the average of the first 1592 even numbers?
(8) Find the average of odd numbers from 9 to 1163
(9) Find the average of odd numbers from 7 to 519
(10) Find the average of the first 3730 odd numbers.