Ask Questions, Get Answers
Menu
X
JEEMAIN Crash Practice
15 Test Series
NEET Crash Practice
15 Test Series
CBSE XII
Math
JEEMAIN
Math
Physics
Chemistry
Practice Test Series
CBSE XI
Math
NEET
Physics
Chemistry
Biology - XII
Biology - XI
Olympiad class V
Math - 5 Test Series
Olympiad class VI
Math - 5 Test Series
studyplans
JEEMAIN Crash Practice
15 Test Series
NEET Crash Practice
15 Test Series
CBSE XII
Math
JEEMAIN
Math
Physics
Chemistry
Practice Test Series
CBSE XI
Math
NEET
Physics
Chemistry
Biology - XII
Biology - XI
Olympiad class V
Math - 5 Test Series
Olympiad class VI
Math - 5 Test Series
mobile
exams
ask
sample papers
tutors
pricing
login
X
ASK
Home
>>
JEEMAIN and NEET
>>
Mathematics
>>
Class11
>>
Statistics
If SD of 15 items is 6 and each item is decreased by 1, find the SD of the new set.
$\begin {array} {1 1} (A)\;10 & \quad (B)\;6 \\ (C)\;11 & \quad (D)\;15 \end {array}$
jeemain
math
cbse
class11
statistics
variance-and-standard-deviation
easy
q90
Share
asked
Jan 31, 2014
by
thanvigandhi_1
retagged
Sep 10, 2014
by
sharmaaparna1
Please
log in
or
register
to add a comment.
Please
log in
or
register
to answer this question.
1 Answer
If each item of a data is increased or decreased by the same amount.
The SD of the data remains unchanged.
$ \therefore $ SD of new set is 15
Ans : (D)
answered
Jan 31, 2014
by
thanvigandhi_1
Please
log in
or
register
to add a comment.
Related questions
The first of the two sample has 100 items with mean 15 and S.D= 3. If the whole group has 250 items with mean 15.6 and SD = $ \sqrt{13.44}$ the S.D of the second group is?
jeemain
math
cbse
class11
statistics
variance-and-standard-deviation
difficult
q38
asked
Jan 31, 2014
by
thanvigandhi_1
1
answer
If SD of $X$ is $ \sigma $ then SD of $ \large\frac{aX+b}{c}$ ( where $a,b,c$ are constants ) is
jeemain
math
cbse
class11
statistics
variance-and-standard-deviation
difficult
q50
asked
Feb 1, 2014
by
thanvigandhi_1
1
answer
If the SD of X is $\sigma_X$ then SD of $\large\frac{aX-b}{c}$ ( where a,b,c are constants ) is:
jeemain
math
cbse
class11
statistics
variance-and-standard-deviation
medium
asked
Jan 27, 2014
by
thanvigandhi_1
1
answer
The coefficient of correlation between $x$ and $y$ is $0.5$ and their covariance is $16$ and SD of $x$ is $4$ then SD of $y$ is
jeemain
math
cbse
class11
statistics
medium
variance-and-standard-deviation
q42
asked
Jan 28, 2014
by
thanvigandhi_1
1
answer
For two data sets each of size 5, the variances are given to be 4 and 5 and the corresponding means are given to be 2 and 4 respectively. The variance of the combined data set is
jeemain
math
cbse
class11
statistics
variance-and-standard-deviation
difficult
q31
asked
Jan 28, 2014
by
thanvigandhi_1
1
answer
If an experiment with 15 observations on $x$ the following results were available: $\Sigma x^2=2830 \: \Sigma x = 170$. One observation that was 20 was found to be wrong and was replaced by the correct value 30. The corrected variance is
jeemain
math
cbse
class11
statistics
variance-and-standard-deviation
difficult
q48
asked
Feb 1, 2014
by
thanvigandhi_1
1
answer
If the variance 1,2,3,4,5....10 is $ \large\frac{99}{12}$ then the standard deviation of 3,6,9,12....30 is
jeemain
math
cbse
class11
statistics
easy
variance-and-standard-deviation
q85
asked
Jan 31, 2014
by
thanvigandhi_1
1
answer
Ask Question
Tag:
Math
Phy
Chem
Bio
Other
SUBMIT QUESTION
►
Please Wait
Take Test
JEEMAIN Crash Practice
15 Test Series
NEET Crash Practice
15 Test Series
JEEMAIN
350+ TESTS
NEET
320+ TESTS
CBSE XI MATH
50+ TESTS
CBSE XII MATH
80+ TESTS
...
X