The problem asks for the sum of the smallest and largest numbers in a group of 8 consecutive even numbers, given that their average is 41.
For any arithmetic sequence (like consecutive even numbers), the average is equal to the average of the first and last term. That is:
$ \text{Average} = \frac{\text{Smallest Number} + \text{Largest Number}}{2} $
We are given that the average of the 8 consecutive even numbers is 41.
Using the property mentioned above:
$ 41 = \frac{\text{Smallest Number} + \text{Largest Number}}{2} $
To find the sum of the smallest and largest numbers, we multiply the average by 2:
$ \text{Smallest Number} + \text{Largest Number} = 41 \times 2 $
$ \text{Smallest Number} + \text{Largest Number} = 82 $
Since there are 8 consecutive even numbers, the average (41) lies between the 4th and 5th numbers. The two middle even numbers must be 40 and 42.
Working backwards and forwards:
The sum of the smallest and largest numbers is 82.
The average of 28 numbers is 77. The average of first 14 numbers is 74 and the average of last 15 numbers is 84. If the 14 th number is excluded, then what is the average of remaining numbers? (correct to one decimal places)
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The average weight of 49 students in a class is 39 kg. Seven of them whose average weight is 40 kg leave the class and other seven students whose average weight is 54 kg join the class. What is the new average weight (in kg) of the class?