UPSC Exam > UPSC Questions > If the mean of 5 observations x, x + 2, x + 4...
Start Learning for Free
If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations is
- a)13
- b)15
- c)17
- d)11
Correct answer is option 'A'. Can you explain this answer?
Most Upvoted Answer
If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, ...
Concept use:
Mean of the observation = Sum of the observations/ Total no of observations
Calculations:
mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11
⇒ mean of 5 observation = x + x + 2 + x + 4 + x + 6 + x + 8/ 5 = 5x + 20/5 = 11
⇒ mean of 5 observation = x + 4 = 11
⇒ x = 7
Mean of Last Observation = x + 4 + x + 6 + x + 8/ 3 = 3x + 18/3 = x + 6 = 7 + 6 = 13
Free Test
FREE
| Start Free Test |
Community Answer
If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, ...
To find the mean of the last 3 observations, we need to first calculate the sum of the last 3 observations and then divide it by 3.
Let's assume the value of x as 'a' to solve the problem.
Given that the mean of the 5 observations is 11, we can write the equation as:
(x + x + 2 + x + 4 + x + 6 + x + 8) / 5 = 11
Simplifying the equation, we get:
(5x + 20) / 5 = 11
5x + 20 = 55
5x = 55 - 20
5x = 35
x = 35 / 5
x = 7
So, the value of x is 7.
Now, we can substitute the value of x in the last 3 observations and calculate their sum:
7 + 7 + 6 = 20
Finally, we can find the mean of the last 3 observations by dividing their sum by 3:
Mean = 20 / 3
Mean = 6.67 (rounded to two decimal places)
Therefore, the mean of the last 3 observations is approximately 6.67.
Since none of the given options match the calculated mean, it seems like there might be a mistake in the question or options provided. The correct answer cannot be determined with the given information.
Let's assume the value of x as 'a' to solve the problem.
Given that the mean of the 5 observations is 11, we can write the equation as:
(x + x + 2 + x + 4 + x + 6 + x + 8) / 5 = 11
Simplifying the equation, we get:
(5x + 20) / 5 = 11
5x + 20 = 55
5x = 55 - 20
5x = 35
x = 35 / 5
x = 7
So, the value of x is 7.
Now, we can substitute the value of x in the last 3 observations and calculate their sum:
7 + 7 + 6 = 20
Finally, we can find the mean of the last 3 observations by dividing their sum by 3:
Mean = 20 / 3
Mean = 6.67 (rounded to two decimal places)
Therefore, the mean of the last 3 observations is approximately 6.67.
Since none of the given options match the calculated mean, it seems like there might be a mistake in the question or options provided. The correct answer cannot be determined with the given information.
|
Explore Courses for UPSC exam
|
|
Similar UPSC Doubts
Top Courses for UPSCView all
If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer?
Question Description
If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer? for UPSC 2025 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for UPSC 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer?.
If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer? for UPSC 2025 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for UPSC 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer?.
Solutions for If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for UPSC.
Download more important topics, notes, lectures and mock test series for UPSC Exam by signing up for free.
Here you can find the meaning of If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer?, a detailed solution for If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer? has been provided alongside types of If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice If the mean of 5 observations x, x + 2, x + 4, x + 6 and x + 8 is 11, then the mean of last 3 observations isa)13b)15c)17d)11Correct answer is option 'A'. Can you explain this answer? tests, examples and also practice UPSC tests.
|
|
Explore Courses for UPSC exam
|
|
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup