Question : What is the average of the first 471 even numbers?
Correct Answer 472
Solution & 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 471 even numbers are
2, 4, 6, 8, . . . . 471 th terms
Calculation of the sum of the first 471 even numbers
We can find the sum of the first 471 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 471 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 471 even number,
n = 471, a = 2, and d = 2
Thus, sum of the first 471 even numbers
S471 = 471/2 [2 × 2 + (471 – 1) 2]
= 471/2 [4 + 470 × 2]
= 471/2 [4 + 940]
= 471/2 × 944
= 471/2 × 944 472
= 471 × 472 = 222312
⇒ The sum of the first 471 even numbers (S471) = 222312
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 471 even numbers
= 4712 + 471
= 221841 + 471 = 222312
⇒ The sum of the first 471 even numbers = 222312
Calculation of the Average of the first 471 even numbers
Formula to find the Average
Average = Sum of the given numbers/Number of the numbers
Thus, The average of the first 471 even numbers
= Sum of the first 471 even numbers/471
= 222312/471 = 472
Thus, the average of the first 471 even numbers = 472 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 471 even numbers = 471 + 1 = 472
Thus, the average of the first 471 even numbers = 472 Answer
Similar Questions
(1) What will be the average of the first 4134 odd numbers?
(2) Find the average of even numbers from 10 to 292
(3) Find the average of even numbers from 12 to 332
(4) What is the average of the first 1539 even numbers?
(5) Find the average of odd numbers from 7 to 447
(6) Find the average of the first 2638 even numbers.
(7) Find the average of the first 3194 even numbers.
(8) What is the average of the first 1929 even numbers?
(9) Find the average of odd numbers from 13 to 1023
(10) Find the average of the first 3664 even numbers.