MHT CET · Maths · Statistics
In an experiment with 15 observations on \(x\), we have \(\sum x^2=2830, \sum x=170\). One observation that was 20 was found to be wrong and was replaced by the correct value 30 , then the corrected variance is
- A 177.33
- B 188.66
- C 80.33
- D 78
Answer & Solution
Correct Answer
(D) 78
Step-by-step Solution
Detailed explanation
\(\text { Correct variance }=\frac{\sum x^2-20^2+30^2}{15}-\) \(\left(\frac{\sum x-20+30}{15}\right)^2 \)
\( =\frac{2830-400+90}{15}-\left(\frac{170-20+30}{15}\right)^2 \)
\( =222-144=78\)
\( =\frac{2830-400+90}{15}-\left(\frac{170-20+30}{15}\right)^2 \)
\( =222-144=78\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Maths
- For all real \(x\), the minimum value of the function \(f(x)=\frac{1-x+x^2}{1+x+x^2}\) isMHT CET 2021 Medium
- \(\int \frac{x+\sin x}{1+\cos x} \mathrm{~d} x=\)MHT CET 2025 Medium
- If \(\lim _{x \rightarrow \infty}\left(\frac{x^2+x+1}{x+1}-a x-b\right)=4\) thenMHT CET 2024 Easy
- The solution of the differential equation \(\left(3 x y+y^{2}\right) d x+\left(x^{2}+x y\right) d y=0\) isMHT CET 2008 Medium
- \(\int \frac{d x}{\cos x \sqrt{\cos 2 x}}=\)MHT CET 2021 Easy
- The points \((1,3)\) and \((5,1)\) are two opposite vertices of a rectangle. The other two vertices are lie on the line \(\mathrm{y}=2 x+\mathrm{c}\) where c is the constant, then co-ordinates of other two vertices areMHT CET 2025 Medium
More PYQs from MHT CET
- A simple pendulum of length ' \(\ell\) ' has a bob of mass 'm'. It executes S.H.M. of small amplitude 'A'. The maximum tension in the string is
\((\mathrm{g}=\) acceleration due to gravity)MHT CET 2020 Hard - A ray of light is incident on one face of an equilateral glass prism having refractive index \(\sqrt{2}\). It produces the emergent ray which just grazes along the adjacent face. The value of angle of incidence isMHT CET 2021 Hard
- Which among the following has the lowest boiling point?MHT CET 2023 Easy
- If the angle between the lines is \(\frac{\pi^c}{4}\) and slope of one of the lines is \(\frac{1}{2}\), then slope of the other line isMHT CET 2021 Easy
- Which of the following pairs of monomers is used for the preparation of dextron?MHT CET 2020 Hard
- If \(f(x)=|x|/x\) for x≠0 and 1 for X=0, then the function isMHT CET 2020 Easy