CA Foundation Exam > CA Foundation Questions > The mean and SD for a group of 100 observatio...
Start Learning for Free
The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?
- a)16
- b)25
- c)4
- d)2
Correct answer is option 'C'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Most Upvoted Answer
The mean and SD for a group of 100 observations are 65 and 7.03 respec...
Given information:
- Mean of 100 observations = 65
- Standard deviation of 100 observations = 7.03
- Mean of 60 observations = 70
- Standard deviation of 60 observations = 3
- We need to find the standard deviation of the remaining 40 observations.
Formula to calculate the combined standard deviation :
SD1 = Standard deviation of first set of observations
SD2 = Standard deviation of second set of observations
n1 = Number of observations in first set
n2 = Number of observations in second set
SD = Standard deviation of the combined set of observations
SD = √[(n1-1)SD1^2 + (n2-1)SD2^2 / (n1+n2-2)]
Calculating the combined standard deviation of the 60 observations:
SD1 = 3
n1 = 60
SD2 = 7.03
n2 = 40
SD60 = √[(60-1)3^2 + (40-1)7.03^2 / (60+40-2)]
SD60 = √[1772.39 / 98]
SD60 = √18.08
SD60 = 4.25
Therefore, the standard deviation of the remaining 40 observations is 4.25, which is closest to option C (4).
- Mean of 100 observations = 65
- Standard deviation of 100 observations = 7.03
- Mean of 60 observations = 70
- Standard deviation of 60 observations = 3
- We need to find the standard deviation of the remaining 40 observations.
Formula to calculate the combined standard deviation :
SD1 = Standard deviation of first set of observations
SD2 = Standard deviation of second set of observations
n1 = Number of observations in first set
n2 = Number of observations in second set
SD = Standard deviation of the combined set of observations
SD = √[(n1-1)SD1^2 + (n2-1)SD2^2 / (n1+n2-2)]
Calculating the combined standard deviation of the 60 observations:
SD1 = 3
n1 = 60
SD2 = 7.03
n2 = 40
SD60 = √[(60-1)3^2 + (40-1)7.03^2 / (60+40-2)]
SD60 = √[1772.39 / 98]
SD60 = √18.08
SD60 = 4.25
Therefore, the standard deviation of the remaining 40 observations is 4.25, which is closest to option C (4).
Attention CA Foundation Students!
To make sure you are not studying endlessly, EduRev has designed CA Foundation study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in CA Foundation.
|
Explore Courses for CA Foundation exam
|
|
Similar CA Foundation Doubts
Top Courses for CA FoundationView all
The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer?
Question Description
The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer? for CA Foundation 2024 is part of CA Foundation preparation. The Question and answers have been prepared according to the CA Foundation exam syllabus. Information about The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for CA Foundation 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer?.
The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer? for CA Foundation 2024 is part of CA Foundation preparation. The Question and answers have been prepared according to the CA Foundation exam syllabus. Information about The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for CA Foundation 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer?.
Solutions for The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for CA Foundation.
Download more important topics, notes, lectures and mock test series for CA Foundation Exam by signing up for free.
Here you can find the meaning of The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer?, a detailed solution for The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer? has been provided alongside types of The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice The mean and SD for a group of 100 observations are 65 and 7.03 respectively. If 60 of these observations have mean and SD as 70 and 3 respectively, what is the SD for the group comprising 40 observations?a)16b)25c)4d)2Correct answer is option 'C'. Can you explain this answer? tests, examples and also practice CA Foundation tests.
|
|
Explore Courses for CA Foundation exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup