Home
Class 11
MATHS
Mean and standard deviation of 100 obser...

Mean and standard deviation of 100 observations were found to be 40 and 10, respectively . If at the time of calculation two observation were wrongly taken as 30 and 70 in place of 3 and 27 respectively, find the correct standard deviation.

Text Solution

Verified by Experts

The correct Answer is:
10.24
Promotional Banner

Topper's Solved these Questions

  • STATISTICS

    KUMAR PRAKASHAN|Exercise NCERT EXEMPLAR PROBLEMS (OBJECTIVE TYPE QUESTIONS)|16 Videos

  • STATISTICS

    KUMAR PRAKASHAN|Exercise NCERT EXEMPLAR PROBLEMS (FILLERS)|6 Videos

  • STATISTICS

    KUMAR PRAKASHAN|Exercise TEXTBOOK ILLUSTRATIONS FOR PRACTICE WORK|19 Videos

  • SETS

    KUMAR PRAKASHAN|Exercise QUESTION OF MODULE|28 Videos

  • STRAIGHT LINES

    KUMAR PRAKASHAN|Exercise Question of Module (Knowledge Test :)|18 Videos

Similar Questions

Explore conceptually related problems

The mean and standard deviation of a random variable X are 10 and 5 respectively. Match the following.

The mean and standard deviation of a group of 100 observations were found to be 20 and 3, respectively. Later on it was found that three observations were incorrect, which were recorded as 21, 21 and 18. Find the mean and standard deviation if the incorrect observations are omitted.

The mean and standard deviation of 20 observations are found to be 10 and 2, respectively. On rechecking , it was found that an observation 8 was incorrect . Calculate the correct mean and standard deviation in each of the following cases: (i) If wrong item is omitted. (ii) If it is replaced by 12.

Mean and standard deviation of 100 items are 50 and 4, respectively . Find the sum of all the item and the sum of the squares of the items.

The mean and standard deviation of a set of n_1 observation are barx_1 and S_1 , respectively while the mean standard deviation of another set of n_2 observations are barx_2 and S_2 , respectively . Show that the standard deviation of the combined set of (n_1+n_2) observations is given by standard deviation sqrt ((n_1(S_1)^2 + n_1(S_2)^2)/(n_1+n_2) + (n_1+n_2 (barx_1 - barx_2)^2)/(n_1-n_2)^2)

Mean and standard deviation of the random variable X are (7)/(3) and (14)/(9) respectively. Then find value of n and p.

Coefficient of variation of two distributions are 50 and 60, and their arithmetic means are 30 and 25 respectively. Difference of their standard deviation is ……

The mean and standard deviation of random variable X are 10 and 5 respectively, then E((X-15)/(5))^(2)= ____

KUMAR PRAKASHAN-STATISTICS-NCERT EXEMPLAR PROBLEMS (SHORT ANSWER TYPE QUESTIONS)
  1. Find the algebraic sum of the deviations of all the observations from ...

    Text Solution

    |

  2. Find the standard deviation of the first n natural numbers.

    Text Solution

    |

  3. the mean and standard deviation of some data for the time taken to com...

    Text Solution

    |

  4. Mean and standard deviation of the random variable X are (7)/(3) and (...

    Text Solution

    |

  5. Two sets each of 20 observations , have the same standard deviation 5....

    Text Solution

    |

  6. The frequency distribution : Where A is a positive integer , ha...

    Text Solution

    |

  7. For the frequency distribution: Find the standard distribution ...

    Text Solution

    |

  8. There are 60 students in a class . The following is the frequency dist...

    Text Solution

    |

  9. The mean life of a sample of 60 bulbs was 650 hours and the standard d...

    Text Solution

    |

  10. Mean and standard deviation of 100 items are 50 and 4, respectively . ...

    Text Solution

    |

  11. If for a distribution sum(x-5) = 3, sum(x - 5)^2 = 43 and the total nu...

    Text Solution

    |

  12. Find the mean variance of the frequency distribution given below :

    Text Solution

    |

  13. Calcualte the mean deviation about the mean for the following frequenc...

    Text Solution

    |

  14. Calcualte the mean deviation from the median of the following data :

    Text Solution

    |

  15. Determine the mean and standard deviation for the following distributi...

    Text Solution

    |

  16. The weights of coffee in 70 jars is shown in the following table: ...

    Text Solution

    |

  17. Determine mean and standard deviation of first n terms of an A.P. whos...

    Text Solution

    |

  18. Following are the marks obtained , out of 100 by two students ravi and...

    Text Solution

    |

  19. Mean and standard deviation of 100 observations were found to be 40 an...

    Text Solution

    |

  20. While calculating the mean and variance of 10 readings, a student wron...

    Text Solution

    |