JEE Main 201610 AprilOnline
- Exam
- JEE Main
- Year
- 2016
- Date
- 10 April
- Mode
- Online
- Subject
- Mathematics
- Chapter
- Statistics
JEE Main 2016 · 10 April · Online · Mathematics · Statistics
The mean of 5 observations is 5 and their variance is 12 . 4 . If...
The mean of observations is and their variance is . If three of the observations are ; then the value of the remaining two is :
Options
- A
- B
- C
- DNone of these
Correct answer
C.
Step-by-step solution
\dfrac{x + y + 1 + 2 + 6}{5} = 5⇒ x + y = 1612.4 = \dfrac{\left(16 + 9 + 1 + {\left(x - 5\right)}^{2} + {\left(y - 5\right)}^{2}\right)}{5}⇒ 62= 26 + {\left(x - 5\right)}^{2} + {\left(y - 5\right)}^{2}⇒ 36 = {\left(x - 5\right)}^{2} + {\left(y - 5\right)}^{2} the equations will become
Solving them and again will get the .
If or
If .
But by shifting the origin back to original position, we get
(or)
y = 0 + 5 = 5
Hence, the values of the remaining two are .