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
CBSE XII Board Exam Series
BES Math
BES Physics
BES Chemistry
BES Biology
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
CBSE XII Board Exam Series
BES Math
BES Physics
BES Chemistry
BES Biology
mobile
exams
ask
sample papers
tutors
pricing
login
X
ASK
Home
>>
JEEMAIN and NEET
>>
Mathematics
>>
Class11
>>
Statistics
Combined mean of two series $x_1\: and \: x_2$ when \[\] $x_1 = 210,\: x_2 = 150, \: n_1=50, \: n_2=100 $ is
$\begin {array} {1 1} (A)\;150 & \quad (B)\;160 \\ (C)\;170 & \quad (D)\;180 \end {array}$
jeemain
math
cbse
class11
statistics
easy
measures-of-dispersion-(mean)
q77
Share
asked
Jan 28, 2014
by
thanvigandhi_1
retagged
Sep 8, 2014
by
sharmaaparna1
Please
log in
or
register
to add a comment.
Please
log in
or
register
to answer this question.
1 Answer
Combined mean = $ \large\frac{n_1x_1+n_2x_2}{n_1+n_2}$
$ = \large\frac{50 \times 210 + 100 \times 150}{50+150}$
$ \large\frac{10500+15000}{200}$
$ = 170$
answered
Jan 28, 2014
by
thanvigandhi_1
Please
log in
or
register
to add a comment.
Related questions
Mean of 100 items is 49. It was discovered that 3 items 60, 70, 80 were wrongly read as 38,22,50 respectively. The correct mean is
jeemain
math
cbse
class11
statistics
easy
measures-of-dispersion-(mean)
q61
asked
Jan 25, 2014
by
thanvigandhi_1
1
answer
The mean and standard deviation of a set of $n_1$ observations are $\bar{x_1}$ and $s_1$ respectively , while the mean and standard deviation of another set of $n_2$ observations are $x_2$ and $s_2$ respectively. Show that the standard deviation of the combined set of $(n_1+n_2)$ observations is given by $ S.D= \sqrt {\large\frac{n_1 (s_1)^2 +n_2 (s_2)^2}{n_1+n_2} +\frac{n_1n_2(\bar {x_1} -\bar {x_2} )^2}{(n_1+n_2)^2}}$
cbse
math
class11
ch15
statistics
exemplar
q47
sec-c
difficult
asked
Jul 9, 2014
by
meena.p
1
answer
If the mean of the set of numbers $ x_1, x_2.....x_n$ is $ \overline x$ then mean of the numbers $ x_i+2i \: \: 1 \leq i \leq n $ is
jeemain
math
cbse
class11
statistics
medium
measures-of-dispersion-(mean)
q31
asked
Jan 25, 2014
by
thanvigandhi_1
1
answer
The mean age of a combined group of men and women is 30 years. If the mean of the age of men and women are respectively 32 and 27, then the percentage of women in the group is
jeemain
math
cbse
class11
statistics
difficult
measures-of-dispersion-(mean)
q28
asked
Jan 26, 2014
by
thanvigandhi_1
1
answer
A group of 10 items has arithmatic mean 6. If the arithmatic mean of 4 of these remaining item is 7.5 then the mean of the remaining item is
jeemain
math
cbse
class11
statistics
easy
measures-of-dispersion-(mean)
q74
asked
Jan 27, 2014
by
thanvigandhi_1
1
answer
A group of 10 items has mean 6. If mean of 4 of these items is 7.5 the mean of remaining items is
jeemain
math
cbse
class11
statistics
easy
measures-of-dispersion-(mean)
q68
asked
Jan 26, 2014
by
thanvigandhi_1
1
answer
The mean of a set of observation is $ \overline x$. If each observation is divided by $ a, a \neq 0$ and then is increased by 10, then mean of the new set is
jeemain
math
cbse
class11
statistics
easy
measures-of-dispersion-(mean)
q67
asked
Jan 26, 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
...