Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Engineering
  • The mean and variance of observations are and <img alt="16" src="http://entrancecorner.codecogs.com/gif.latex?16"

The mean and variance of 7 observations are 8 and 16, respectively .If five observations are 2,4,10,12,14, then the absolute difference of the remaining two observations is :
Option: 1 1
Option: 2 4
Option: 3 2
Option: 4 3

Answers (1)

best_answer

\begin{aligned} &\bar{x}=\frac{2+4++10+12+14+x+y}{7}=8\\ &x+y=14\;\;\;\;\;\;\;\;\;\;\ldots(1) \end{aligned}

\\(\sigma)^{2}=\frac{\sum\left(\mathrm{x}_{\mathrm{i}}\right)^{2}}{\mathrm{n}}-\left(\frac{\sum \mathrm{x}_{\mathrm{i}}}{\mathrm{n}}\right)^{2} \\ 16=\frac{4+16+100+144+196+\mathrm{x}^{2}+\mathrm{y}^{2}}{7}-8^{2} \\ 16+64=\frac{460+\mathrm{x}^{2}+\mathrm{y}^{2}}{7}

\begin{aligned} &560=460+x^{2}+y^{2}\\ &\mathrm{x}^{2}+\mathrm{y}^{2}=100\;\;\;\;\;\;\;\;\;\;\;\ldots(2)\\ &\text { Clearly by (i) and (ii), }|x-y|=2 \end{aligned}

Posted by

himanshu.meshram

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

JAC Chandigarh Counselling 2025: Round 1 seat allotment result out for BTech admissions
anam-khan

JoSAA round 5 seat allotment result 2025 out on josaa.nic.in
anam-khan

BTech aspirant from north-east or UT? Apply for CSAB NEUT counselling 2025 today

Latest Question