Question:
What is the average of the first 1274 even numbers?
Correct Answer
1275
Solution And Explanation
Explanation
Method to find the average
Step : (1) Find the sum of given numbers
Step: (2) Divide the sum of given number by the number of numbers. This will give the average of the given numbers
The first 1274 even numbers are
2, 4, 6, 8, . . . . 1274 th terms
Calculation of the sum of the first 1274 even numbers
We can find the sum of the first 1274 even numbers by simply adding them, but this is a bit difficult. And if the list is long, it is very difficult to find their sum. So, in such a situation, we will use a formula to find the sum of given numbers that form a particular pattern.
Here, the list of the first 1274 even numbers forms an Arithmetic series
In an Arithmetic Series, the common difference is the same. This means the difference between two consecutive terms are same in an Arithmetic Series.
The sum of n terms of an Arithmetic Series
Sn = n/2 [2a + (n – 1) d]
Where, n = number of terms, a = first term, and d = common difference
In the series of the first 1274 even number,
n = 1274, a = 2, and d = 2
Thus, sum of the first 1274 even numbers
S1274 = 1274/2 [2 × 2 + (1274 – 1) 2]
= 1274/2 [4 + 1273 × 2]
= 1274/2 [4 + 2546]
= 1274/2 × 2550
= 1274/2 × 2550 1275
= 1274 × 1275 = 1624350
⇒ The sum of the first 1274 even numbers (S1274) = 1624350
Shortcut Method to find the sum of the first n even numbers
Thus, the sum of the first n even numbers = n2 + n
Thus, the sum of the first 1274 even numbers
= 12742 + 1274
= 1623076 + 1274 = 1624350
⇒ The sum of the first 1274 even numbers = 1624350
Calculation of the Average of the first 1274 even numbers
Formula to find the Average
Average = Sum of the given numbers/Number of the numbers
Thus, The average of the first 1274 even numbers
= Sum of the first 1274 even numbers/1274
= 1624350/1274 = 1275
Thus, the average of the first 1274 even numbers = 1275 Answer
Shortcut Trick to find the Average of the first n even numbers
(1) The average of the first 2 even numbers
= 2 + 4/2
= 6/2 = 3
Thus, the average of the first 2 even numbers = 3
(2) The average of the first 3 even numbers
= 2 + 4 + 6/3
= 12/3 = 4
Thus, the average of the first 3 even numbers = 4
(3) The average of the first 4 even numbers
= 2 + 4 + 6 + 8/4
= 20/4 = 5
Thus, the average of the first 4 even numbers = 5
(4) The average of the first 5 even numbers
= 2 + 4 + 6 + 8 + 10/5
= 30/5 = 6
Thus, the average of the first 5 even numbers = 6
Thus, the Average of the First n even numbers = n + 1
Thus, the average of the first 1274 even numbers = 1274 + 1 = 1275
Thus, the average of the first 1274 even numbers = 1275 Answer
Similar Questions
(1) Find the average of the first 2421 odd numbers.
(2) Find the average of odd numbers from 7 to 55
(3) Find the average of the first 3993 odd numbers.
(4) What is the average of the first 780 even numbers?
(5) What is the average of the first 1725 even numbers?
(6) Find the average of even numbers from 12 to 522
(7) Find the average of the first 3359 odd numbers.
(8) Find the average of odd numbers from 7 to 455
(9) Find the average of odd numbers from 11 to 769
(10) Find the average of the first 4139 even numbers.