Home
Class 12
MATHS
Average height & variance of 5 students ...

Average height & variance of `5` students in a class is `150` and `18` respectively. A new student whose height is `156 cm` is added to the group. Find new variance. (a) `20` (b) `22` (c) `16` (d) `14`

A

22

B

20

C

16

D

18

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

Similar Questions

Explore conceptually related problems

The average height of the students in a class of 10 is 105 cm .If 20 more students with an average height of 120 cm join the class , what will the new average height be ?

5 students of a class have an average height 150cm and variance 18cm^(2) .A new student,whose height is 156cm joined them.The variance (in cm^(2) ) of the height of these six students is:

The average height of 8 students is 152 cm. Two more students of heights 144 cm and 155 cm join the group. What is the new average height?

The mean height of a group of 30 students is 150 cm. If a 150 cm tall student is included in the group, then find the mean heigh of the new group.

Average age of 17 student of a class is 16 years. If a new student join the class then average age becomes 20. Then find the age of new student.

The average height of 22 students of a class is 140 cm and the average height of 28 students of another class is 152 cm. What is the average height of students of both the classes?

The mean height of a group of 30 students is 150 cm. If a 150 cm tall student is included in the group , then the mean height of the new group is ___.

CENGAGE-JEE 2019-MCQ
  1. The Boolean expression ~(pvvq)vv(~p^^q) is equivalent to (1) ~p (2) p ...

    Text Solution

    |

  2. (~pvv~q) is logically equivalent to

    Text Solution

    |

  3. Average height & variance of 5 students in a class is 150 and 18 respe...

    Text Solution

    |

  4. A data consists of n observations x(1), x(2), ..., x(n). If Sigma(i=1)...

    Text Solution

    |

  5. The mean of five observations is 5 and their variance is 9.20. If thr...

    Text Solution

    |

  6. The mean and standart deviation of five observations x1,x2,x3,x4,x5 an...

    Text Solution

    |

  7. The outcome of each of 30 items was observed , 10 items gave an outcom...

    Text Solution

    |

  8. Contrapositive of the statement ''If two numbers are not equal, then t...

    Text Solution

    |

  9. There are 30 white balls and 10 red balls in bag. 16 balls are drawn w...

    Text Solution

    |

  10. If the sum of the deviations of 50 observations from 30 is 50, then th...

    Text Solution

    |

  11. Mean and variance of five observations are 4 and 5.2 respectively. If ...

    Text Solution

    |

  12. The system of linear equations x + y + z = 2 2x + 3y + 2z = 5 2...

    Text Solution

    |

  13. If the system of linear equations x-4y+7z=g, 3y-5z=h, -2x+5y-9z=k is c...

    Text Solution

    |

  14. If the system fo equations x+y+z = 5 x + 2y + 3z = 9 x + 3y + a...

    Text Solution

    |

  15. Let a(1),a(2),a(3), …, a(10) be in G.P. with a(i) gt 0 for i=1, 2, …, ...

    Text Solution

    |

  16. If the system of linear equations 2x+2y+3z=a 3x-y+5z=b x-3y+2z=...

    Text Solution

    |

  17. prove that [ [a-b-c , 2a , 2a ] , [2b , b-c-a , 2b ] ,[2c ,2c,c-a-b]]=...

    Text Solution

    |

  18. An ordered pair (alpha, beta) for which the system of linear equations...

    Text Solution

    |

  19. The set of all values of lambda for which the system of linear equatio...

    Text Solution

    |

  20. If A = [(costheta,-sintheta),(sintheta,costheta)], then the matrix A^(...

    Text Solution

    |