Home
Class 12
MATHS
Mean and variance of 20 observation are ...

Mean and variance of 20 observation are 10 and 4. It was found, that in place of 11, 9 was taken by mistake find correct variance.

A

4.02

B

3.99

C

3.98

D

4.01

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • JEE MAIN

    JEE MAINS PREVIOUS YEAR ENGLISH|Exercise MATHEMATICS|121 Videos

  • INVERSE TRIGONOMETRIC FUNCTIONS

    JEE MAINS PREVIOUS YEAR ENGLISH|Exercise All Questions|2 Videos

  • JEE MAINS

    JEE MAINS PREVIOUS YEAR ENGLISH|Exercise All Questions|445 Videos

Similar Questions

Explore conceptually related problems

The mean and variance of 10 observation are found to be 10 and 4 respectively. On rechecking it was found that an observation 8 was incorrect. If it is replaced by 18, then the correct variance is

The mean and variance of 5 observations are respectively 4.4 and 8.24. If three observation are 1,2 and 4 then find the remaining two observations.

The mean and variance of 10 observations are found to be 10 and 5 respectively. On rechecking it is found that an observation 5 is incorrect. If the incorrect observation is replaced by 15, then the correct variance is

The mean and variance of 7 observations are 7 and 22 respectively. If 5 of the observations are 2, 4, 10, 12, 14, then the remaining 2 observations are

The mean and variance of 8 observations are respectively 9 and 9.25. If six observations are 4,6,7,8,12 and 13 then find the remaining two observations.

The mean and variance of 7 observations are 8 and 16, respectively. If five of the observations are 2, 4, 10, 12, 14. Find the remaining two observations.

The mean and variance of 7 observation is 8 and 16. If five of the observations are 2, 4, 10, 12, 14. Find the remaining two observations.

The mean and variance of seven observations are 8 and 16 respectively. If five of these are 2,4,10,12 and 14, then find the remaining two observations.

Mean and variance of five observations are 4 and 5.2 respectively. If three of these observations are 3, 4, 4 then find absolute difference between the other two observations (A) 3 (B) 7 (C) 2 (D) 5

Mean and variance of five observations are 4 and 5.2 respectively. If three of these observations are 3, 4, 4 then find absolute difference between the other two observations (A) 3 (B) 7 (C) 2 (D) 5

JEE MAINS PREVIOUS YEAR ENGLISH-JEE MAIN-MATH
  1. If a hyperbola has vertices (±6, 0) and P(10, 16) lies on it, then the...

    Text Solution

    |

  2. It the 10^(th) term of an A. P. is 1/20 and its 20^(th) term is 1/10, ...

    Text Solution

    |

  3. Let A=[[2,2],[9,4]] and I=[[1,0],[0,1]] then value of 10 A^(-1) is-

    Text Solution

    |

  4. Let alpha=(-1+isqrt(3))/2 and a=(1+alpha)sum(k=0)^(100) alpha^(2k),b=s...

    Text Solution

    |

  5. lambda x + 2y + 2z = 5, 2lambda x + 3y + 5z = 8, 4x + lambda y + 6z =...

    Text Solution

    |

  6. Let veca=hati-2hatj+hatkand vecb=hati-hatj+hatk be two vectors. If vec...

    Text Solution

    |

  7. Let f(x) = (x[x])/(x^2+1) : (1, 3) rarr R then range of f(x) is (where...

    Text Solution

    |

  8. lim(x rarr 0)(int0^x tsin(10t)dt)/x is equal to

    Text Solution

    |

  9. Normal at (2, 2) to curve x^2 + 2xy – 3y^2 = 0 is L. Then perpendicula...

    Text Solution

    |

  10. Let A and B two events such that the probability that exactly one of t...

    Text Solution

    |

  11. The differential equation of the family of curves, x^(2)=4b(y+b),b in ...

    Text Solution

    |

  12. Let P be the set of points (x, y) such that x^2 le y le – 2x + 3. Then...

    Text Solution

    |

  13. Image of (1, 2, 3) w.r.t a plane is (-7/3,-4/3,-1/3) then which of th...

    Text Solution

    |

  14. Mean and variance of 20 observation are 10 and 4. It was found, that i...

    Text Solution

    |

  15. Let coefficient of x^4 and x^2 in the expansion of (x+sqrt(x^2-1))^6+(...

    Text Solution

    |

  16. Solution set of 3^x (3^x –1) + 2 = |3^x –1| + |3^x – 2| contains

    Text Solution

    |

  17. If I=int(1)^(2)(dx)/(sqrt(2x^(3)-9x^(2)+12x+4)), then

    Text Solution

    |

  18. Let f(x) is a three degree polynomial for which f ' (–1) = 0, f '' (1)...

    Text Solution

    |

  19. If sqrt2(sin alpha)/(sqrt(1+cos2 alpha))=1/7 and sqrt((1-cos2beta)/2)=...

    Text Solution

    |

  20. Let the line y = mx intersects the curve y^2 = x at P and tangent to y...

    Text Solution

    |